Been working on the 52 Chevy Coupe I bought last August. Did some body work on one side, ended up sanding the door and rear quarter down to bare metal. It looks like the car was painted with enamel over the original lacquer. Should I sand the rest of the car down to bare metal or would just roughing of the remaining paint be OK? I want to shoot it with basecoat- clearcoat as a finish? What grit paper would I rough it up with? Thanks, Coach Frank