Yay! A question I know about. I was a picture framer and rub 'n' buff was originally a product for touching up frames. It is made of wax, pigment, and an oily solvent. It never dries completely. Clear coat will lay on top of it, but will not bond to it. A lacquer-based clear coat will work best. No matter what you do, it will scuff easily. If you finish the prop and leave it on the shelf, you're O.K. But it will rub off otherwise.