diff --git a/restoration/source410/BT/GYRO.CPP b/restoration/source410/BT/GYRO.CPP
index 5e7af23e..49f97277 100644
--- a/restoration/source410/BT/GYRO.CPP
+++ b/restoration/source410/BT/GYRO.CPP
@@ -469,7 +469,14 @@ void
 	direction *= magnitude;
 	bodyForce += direction;
 	bodyForce.y = 0.0f;
-	bodyForce.Negate(bodyForce);
+	//
+	// 5.3.130 CORRECTION: the binary (@004b2de4) negates ONLY the x
+	// component in place -- `*(+0x308) = -*(+0x308)` -- after zeroing y at
+	// +0x30c.  Vector3D::Negate flips all three, so our z carried the
+	// wrong sign on every damage shake and collision crunch since this
+	// function landed.
+	//
+	bodyForce.x = -bodyForce.x;
 }
 
 void
diff --git a/restoration/source410/BT/MECH4.NOTES.md b/restoration/source410/BT/MECH4.NOTES.md
index 4356a14d..727aa701 100644
--- a/restoration/source410/BT/MECH4.NOTES.md
+++ b/restoration/source410/BT/MECH4.NOTES.md
@@ -447,3 +447,31 @@ streamed value.  Both halves now land together.
 
 Soak: `[mobility] scale 1 over 1 myomers` on an undamaged bhk1 -- throttle
 unscaled, drive unchanged (demand 35.9, speed 7.0), zero faults.
+
+## 5.3.130 -- two findings from re-reading landed code
+
+**A REAL SIGN BUG, fixed.**  `Gyroscope::ApplyDamageTorque` (binary
+@004b2de4) ended with `bodyForce.Negate(bodyForce)`, but the binary
+negates ONLY the x component in place (`*(+0x308) = -*(+0x308)`) after
+zeroing y at +0x30c.  `Vector3D::Negate` flips all three, so the z
+component has carried the wrong sign on every damage shake and every
+collision crunch since the function landed.  Fixed to `bodyForce.x =
+-bodyForce.x`.  STILL WORTH A LOOK: `ApplyVerticalImpulse` ends with
+`bodyForce.y = bodyForce.x`, which is odd enough to want its binary
+address found and checked the same way.
+
+**THE DAMAGE AVERAGES: computed, consumed by nobody -- NOT landed.**
+`@0049fe80` (the master perf's second census) writes three means to
+mech+0x354 / +0x358 / +0x35c: over the HULL zones, over every subsystem's
+private zone, and over the MYOMERS' private zones (the 0x51155c test --
+the same GUID the mobility scan proved).  Default 0.0 (@0049ffc8) when a
+count is empty.
+
+A reader hunt found none.  The apparent hits at part_013:9498 and 13728
+are on OTHER objects at the same offsets -- the gyro's damage multipliers
+inside its damage fan-out (@004b2980) and a myomers cell inside the
+myomer simulation (@004b8d18) -- a reminder that offsets are per-class and
+a bare `+ 0x354)` grep proves nothing.  No Mech attribute row binds them
+either.  Landing them would be three loops feeding dead memory, so per the
+project rule (record where the binary is silent, never invent a consumer)
+this stays decoded and unlanded until a consumer turns up.