I played bass a little several years ago and recently decided to start back. Picked up a bass and the guy gave me an old amp that was stored in his shed. It works but it’s in pretty rough shape. Looks like it had carpet but it came off. Looks like most of the dirt and grime is stuck a layer of adhesive residue possibly left when the carpet was removed. Any advice on removing the film without ruining the surface underneath? I’m assuming the later underneath is tolex? It’s bonded to the cheap wood underneath so I have to be careful.