diff --git a/src/components/orders-review-modal.test.tsx b/src/components/orders-review-modal.test.tsx
index d8e0718..f265bbe 100644
--- a/src/components/orders-review-modal.test.tsx
+++ b/src/components/orders-review-modal.test.tsx
@@ -248,4 +248,89 @@ describe("OrdersReviewModal", () => {
     // Cost should now show 33.33.
     expect(screen.getByDisplayValue("33.33")).toBeInTheDocument();
   });
+
+  it("renders PDF preview via iframe when first attachment is a PDF", () => {
+    render(
+      <OrdersReviewModal
+        {...baseProps()}
+        attachments={[
+          {
+            id: "att-1",
+            created: "",
+            updated: "",
+            collectionId: "coll-1",
+            collectionName: "quote_attachments",
+            quote: "quote-1",
+            filename: "Acme-RFQ.pdf",
+            file: ["acme-token"],
+            content_type: "application/pdf",
+            size_bytes: 1000,
+            email_message_id: "",
+            kind: "pdf",
+          },
+        ]}
+      />,
+    );
+    const iframe = document.querySelector("iframe");
+    expect(iframe).toBeInTheDocument();
+    expect(iframe?.getAttribute("src")).toBe(
+      "/api/v1/files/coll-1/att-1/acme-token",
+    );
+  });
+
+  it("renders image preview via <img> when first attachment is an image", () => {
+    render(
+      <OrdersReviewModal
+        {...baseProps()}
+        attachments={[
+          {
+            id: "att-1",
+            created: "",
+            updated: "",
+            collectionId: "coll-1",
+            collectionName: "quote_attachments",
+            quote: "quote-1",
+            filename: "site-photo.jpg",
+            file: ["photo-token"],
+            content_type: "image/jpeg",
+            size_bytes: 1000,
+            email_message_id: "",
+            kind: "image",
+          },
+        ]}
+      />,
+    );
+    const img = document.querySelector("img");
+    expect(img).toBeInTheDocument();
+    expect(img?.getAttribute("src")).toBe(
+      "/api/v1/files/coll-1/att-1/photo-token",
+    );
+  });
+
+  it("renders 'no preview' list when attachments are not PDF/image", () => {
+    render(
+      <OrdersReviewModal
+        {...baseProps()}
+        attachments={[
+          {
+            id: "att-1",
+            created: "",
+            updated: "",
+            collectionId: "coll-1",
+            collectionName: "quote_attachments",
+            quote: "quote-1",
+            filename: "doc.docx",
+            file: ["docx-token"],
+            content_type:
+              "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+            size_bytes: 1000,
+            email_message_id: "",
+            kind: "doc",
+          },
+        ]}
+      />,
+    );
+    expect(screen.getByText(/no preview/i)).toBeInTheDocument();
+    expect(screen.getByText("doc.docx")).toBeInTheDocument();
+  });
 });
diff --git a/src/components/orders-review-modal.tsx b/src/components/orders-review-modal.tsx
index 711ffd9..cbcb44c 100644
--- a/src/components/orders-review-modal.tsx
+++ b/src/components/orders-review-modal.tsx
@@ -514,7 +514,10 @@ export function OrdersReviewModal({
   );
 }
 
-// --- Source-of-truth panel (filled out in Task 5) -------------------------
+// --- Source-of-truth panel -----------------------------------------------
+// Inline preview of the source attachment so the operator can scan
+// the actual PDF/image against the order items in one screen.
+// Falls back to the email body when no attachments exist.
 function SourceOfTruth({
   quoteEmail,
   attachments,
@@ -523,32 +526,143 @@ function SourceOfTruth({
   attachments: QuoteAttachment[];
 }) {
   if (attachments.length === 0) {
-    return (
-      <div className="rounded-md border bg-muted/30 p-3 text-xs space-y-2">
-        <div className="flex items-center gap-1.5 font-semibold uppercase tracking-wide text-muted-foreground">
-          <Mail className="h-3 w-3" />
-          Email
-        </div>
-        <p className="text-foreground font-medium">{quoteEmail.subject || "(no subject)"}</p>
-        <pre className="whitespace-pre-wrap font-sans text-muted-foreground max-h-64 overflow-y-auto">
-          {quoteEmail.body || "(no body)"}
-        </pre>
-      </div>
-    );
+    return <EmailFallback quoteEmail={quoteEmail} />;
   }
+
+  // Pick the first PDF if any, else first image, else the first
+  // entry of any other kind (which gets the "no preview" treatment).
+  const firstPdf = attachments.find((a) => a.kind === "pdf");
+  const firstImage = attachments.find((a) => a.kind === "image");
+  const firstOther = attachments.find(
+    (a) => a.kind !== "pdf" && a.kind !== "image",
+  );
+
+  const previewTarget = firstPdf ?? firstImage ?? null;
+  const othersAreUnpreviewable = attachments.some(
+    (a) => a.kind !== "pdf" && a.kind !== "image",
+  );
+
   return (
-    <div className="rounded-md border bg-muted/30 p-3 text-xs space-y-2">
-      <div className="flex items-center gap-1.5 font-semibold uppercase tracking-wide text-muted-foreground">
+    <div className="rounded-md border bg-muted/30 text-xs space-y-3">
+      <div className="px-3 pt-3 flex items-center gap-1.5 font-semibold uppercase tracking-wide text-muted-foreground">
         <Paperclip className="h-3 w-3" />
-        Attachments ({attachments.length}) — preview added in Task 5
+        Attachments ({attachments.length})
       </div>
-      <ul className="space-y-1">
+
+      {/* Tab strip — one chip per attachment, primary chip = previewTarget */}
+      {attachments.length > 1 && (
+        <div className="px-3 flex flex-wrap gap-1.5 border-b border-border/40 pb-2">
+          {attachments.map((a) => {
+            const isActive = previewTarget && a.id === previewTarget.id;
+            const previewable = a.kind === "pdf" || a.kind === "image";
+            return (
+              <span
+                key={a.id}
+                className={cn(
+                  "inline-flex items-center gap-1 rounded-full px-2 py-0.5 leading-5 text-[10px]",
+                  isActive
+                    ? "bg-primary/15 text-primary font-medium"
+                    : "text-muted-foreground",
+                )}
+                title={`${a.filename} (${a.kind ?? "unknown"})`}
+              >
+                {previewable ? "●" : "○"} {a.filename}
+              </span>
+            );
+          })}
+        </div>
+      )}
+
+      {previewTarget && previewTarget.kind === "pdf" && (
+        <iframe
+          src={attachmentUrl(previewTarget)}
+          title={previewTarget.filename}
+          className="w-full h-[420px] bg-background border-t"
+          data-testid="review-attachment-iframe"
+        />
+      )}
+
+      {previewTarget && previewTarget.kind === "image" && (
+        <div className="px-3 pb-3">
+          {/* eslint-disable-next-line @next/next/no-img-element */}
+          <img
+            src={attachmentUrl(previewTarget)}
+            alt={previewTarget.filename}
+            className="max-w-full max-h-[420px] rounded border bg-background"
+            data-testid="review-attachment-img"
+          />
+        </div>
+      )}
+
+      {/* No previewable attachment at all — show a no-preview message. */}
+      {!previewTarget && firstOther && (
+        <div className="px-3 pb-3 space-y-1">
+          <p
+            className="text-muted-foreground italic"
+            data-testid="review-no-preview"
+          >
+            {`No preview available for this ${firstOther.kind ?? "file"} type.`}
+          </p>
+        </div>
+      )}
+
+      {othersAreUnpreviewable && previewTarget && (
+        <div className="px-3 pb-3">
+          <p className="text-[10px] text-muted-foreground">
+            + {attachments.filter(
+              (a) => a.kind !== "pdf" && a.kind !== "image",
+            ).length}{" "}
+            unpreviewable attachment(s) — open to view.
+          </p>
+        </div>
+      )}
+
+      <ul className="px-3 pb-3 space-y-1">
         {attachments.map((a) => (
-          <li key={a.id} className="text-muted-foreground truncate">
-            {a.filename}
+          <li
+            key={a.id}
+            className="flex items-center justify-between gap-2 text-[11px]"
+          >
+            <span className="truncate text-muted-foreground">
+              {a.filename}
+            </span>
+            <a
+              href={attachmentUrl(a)}
+              target="_blank"
+              rel="noopener noreferrer"
+              className="text-primary hover:underline inline-flex items-center gap-0.5"
+            >
+              open <ExternalLink className="h-2.5 w-2.5" />
+            </a>
           </li>
         ))}
       </ul>
     </div>
   );
 }
+
+function EmailFallback({
+  quoteEmail,
+}: {
+  quoteEmail: { subject: string; body: string };
+}) {
+  return (
+    <div className="rounded-md border bg-muted/30 p-3 text-xs space-y-2">
+      <div className="flex items-center gap-1.5 font-semibold uppercase tracking-wide text-muted-foreground">
+        <Mail className="h-3 w-3" />
+        Email
+      </div>
+      <p className="text-foreground font-medium">
+        {quoteEmail.subject || "(no subject)"}
+      </p>
+      <pre className="whitespace-pre-wrap font-sans text-muted-foreground max-h-[420px] overflow-y-auto">
+        {quoteEmail.body || "(no body)"}
+      </pre>
+    </div>
+  );
+}
+
+function attachmentUrl(a: QuoteAttachment): string {
+  const token = Array.isArray(a.file) ? a.file[0] : a.file;
+  return `/api/v1/files/${a.collectionId}/${a.id}/${token}`;
+}