On my 1974 low mile Z the previous owner went nuts with black spray bomb on the floorboards and gas tank. The gas tank was spray bombed black, then pin striped
I read where oven cleaner would remove spray bomb paint so I tried it on the tank where you couldnt see it. I sprayed it and let it sit and then basically washed off the paint.
I ended up doing the whole tank. Results were amazing as it looked like a brand new tank.
I could even see the factory USS stencil marking on the tank.
Here are pics after I did this.