diff --git a/B06_Section/logic/B06_Section_Station_Swap.ts b/B06_Section/logic/B06_Section_Station_Swap.ts
index 897bbc320..30e03b2c9 100644
--- a/B06_Section/logic/B06_Section_Station_Swap.ts
+++ b/B06_Section/logic/B06_Section_Station_Swap.ts
@@ -193,7 +193,7 @@ export function swapCrossSections(
   oldKeys: ReadonlyArray<string>,
   intervalM: number | null,
   routeDraft = false,
-  saved: ReadonlyArray<Partial<CanonPlace>> = [],
+  saved: ReadonlyArray<Partial<CanonPlace & Pick<CrossSection, "design">>> = [],
 ): StationSwap {
   const byKey = new Map(detail.cross_sections.map((section, i) => [oldKeys[i], section]));
   const used = new Set<CrossSection>();
@@ -301,7 +301,18 @@ export function swapCrossSections(
       : fresh
         ? uphillSide(station)
         : (prior?.uphill_side ?? null);
-    if (!prior) return { ...place, uphill_side: uphill, samples, design: freshDesign(uphill) };
+    // 지금 상세에 없던 측점이 정본 자리로 돌아옴(관 지움 ↶ 등) = 정본 설계(472 덧 · 지우기 전과 같음)
+    const restored =
+      !prior && !routeDraft && !detail.cross_sections.some(atPlace)
+        ? saved.find((row): boolean => atPlace(row))
+        : undefined;
+    if (!prior)
+      return {
+        ...place,
+        uphill_side: uphill,
+        samples,
+        design: restored?.design ? { ...restored.design } : freshDesign(uphill),
+      };
     const reseed =
       (station.kind === "pipe" || station.kind === "structure") &&
       Math.abs(prior.chainage_m - station.chainageM) > FACILITY_RESEED_M;
diff --git a/resources/tester/helper_272_swap_canon.mjs b/resources/tester/helper_272_swap_canon.mjs
index f73030665..9b282925c 100644
--- a/resources/tester/helper_272_swap_canon.mjs
+++ b/resources/tester/helper_272_swap_canon.mjs
@@ -212,6 +212,26 @@ const out = {};
   out.pipeGone.canon = report(after)["40.00"].same;
 }
 
+/* 1-5. 관 지움 → 되돌림(472 덧) — 지금 상세에 없던 측점이 정본 자리로 = 정본 설계(빈 기본 설계 아님) */
+{
+  const all = stationsAt(45);
+  const without = all.filter((s) => s.key !== "pipe:p1");
+  const gone = m.swapCrossSections(canonDetail(), without, KEYS, 20, false);
+  const saved = canonDetail().cross_sections;
+  const back = m.swapCrossSections(gone.detail, all, keysOf(without), 20, false, saved);
+  const at45 = back.detail.cross_sections.find((s) => s.chainage_m === 45);
+  const bare = m
+    .swapCrossSections(gone.detail, all, keysOf(without), 20, false)
+    .detail.cross_sections.find((s) => s.chainage_m === 45);
+  out.pipeRestore = {
+    design: json(at45.design) === json(canonOf.get(45).design),
+    copy: at45.design !== saved.find((s) => s.chainage_m === 45).design,
+    place: report(back.detail)["45.00"].same,
+    bytes: bytesSame(back.detail, [45]),
+    bareFresh: bare.design?.mark === undefined, // 정본 없음 = 기본 설계 그대로
+  };
+}
+
 /* 2. 가게 길(swapSectionStations) — 가게 routeDraft 로 가름: 없음 · 있음 · 초안 버린 직후 */
 const seed = (P, R) => {
   m.writeState("section-detail", canonDetail(), P, R);
diff --git a/resources/tester/test_272_swap_keeps_canon.py b/resources/tester/test_272_swap_keeps_canon.py
index e52eca43a..8e06f1e81 100644
--- a/resources/tester/test_272_swap_keeps_canon.py
+++ b/resources/tester/test_272_swap_keeps_canon.py
@@ -114,7 +114,9 @@ def test_가게_길_초안_있음_버린_직후(out):
     for at in STRAIGHT:  # 초안 차례 = 옛 규칙(기하 새 틀 · 표본 앞 값)
         assert not s["draft"][at]["same"] and not s["draft"][at]["browser"], at
     dropped = s["dropped"]
-    for at in CURVES:  # 버린 뒤 = 저장 정본 자리 · 표본(초안 3 cm 자리 표본이 안 남음 · 467 덧 정본 물러섬)
+    for at in (
+        CURVES
+    ):  # 버린 뒤 = 저장 정본 자리 · 표본(초안 3 cm 자리 표본이 안 남음 · 467 덧 정본 물러섬)
         assert dropped[at]["same"] and not dropped[at]["browser"], at
     for at in STRAIGHT:  # 초안이 안 옮긴 측점 = 앞 횡단 표본(서버) 그대로
         assert not dropped[at]["browser"], at
@@ -133,3 +135,10 @@ def test_일반_측점_자리_관_지움_다른_목록(out):
     assert g["sameUntouched"] is True  # 일반 측점 그대로 = 같은 목록
     assert g["culvertLeft"] is False and g["kind"] == "regular"  # 관 카드 안 남음
     assert g["canon"]  # 그 자리 정본 표본 · 기하
+
+
+def test_관_지움_되돌림_정본_설계(out):
+    r = out["pipeRestore"]
+    assert r["design"] and r["copy"]  # 지우기 전 설계(정본 사본) — 빈 기본 설계 아님(472 덧)
+    assert r["place"] and r["bytes"]
+    assert r["bareFresh"]