Yeah actually I just figured out how to do it.
There's a Transform button when you're looking at the Gun Point in PCS2, and a Translate tab within the Transform window. It takes some guesswork but I just translated in negatively along the Y axis.
In this case the model is super simple since it was supposed to be a minimal enemy-only fighter. So there's actually no gun barrel. That also explains why it wasn't meant to look right for the player.
If I ever have to do this on a ship with
a gun barrel... well... too bad.