I've picked up a GPW...

[maple_leaf_eh]

Agreed on respecting the original as-found condition of this vehicle. As much as it might look like a junkyard find, it is a remarkable survivor. In some circles, you have found the equivalent of the lottery prize.

My suggestion would be to make it safe for the road and serviceable to run, but do as little as possible to the externals. Imagine yourself as a theatre makeup artist or set designer. Do nothing that will draw attention to your modern work. I don't know what can be done to arrest the surface rust and peeling paint. Maybe just acknowledge the forces of physics and try to keep it dry.