Here’s a pic of some finish damage on a PB Standard I had. Notice the clear is on top of the blue (that’s why they turn green and white turns yellow).
I don’t know what type of paint they use but nitro over poly is supposedly a no no.
‘21 has the cap between the middle wiper lug of the tone pot and the casing.
I also found this thread- https://www.everythingsg.com/threads/lp-sg-wiring-changes-a-history.19281/
The 70 Junior looked similar-
Another possibility… when you have the new string loosely mounted at the bridge / tailpiece and through the hole of the tuner… BEFORE you bend it or tighten it, make sure there is no twist in it longways down the neck before tightening.