I understand you're trying to help, but making cracks about Americans is neither a help, nor is it appreciated. If it is not a GB, and simply has GB decals on it, that would imply a fraudulent representation, would it not? Either way I would like to find out the builder of this frame, whether it be GB sourced or not. You asked for several bits of info, which I supplied to the best of my ability. I understand the point(s) you are making, you make them on every post? They have already been established, so mentioning them over and over is beating a dead horse.
Any paint that is not clear coated, will leave paint color on a rag, buffer, or anything you use to polish it with. It matters not what type of paint it is. Cellulose lacquer, acrylic lacquer, acrylic enamel, etc. I used to paint/detail cars for a living, so I know paint. Up to a point in the late sixties to early seventies, every bike, or car, or anything with a paint finish as a protective coating was a single stage process, and will therefore transfer color to whatever you're polishing it with.
BTW: My Grandmother on my Mother's side was killed in a VW Beetle before I ever had a chance to meet her. She was in the passengers side when the VW was hit head on by drunken idiot who drove up an exit ramp.... The car crumpled up like the tin can that it was. The Beetle is as unsafe as a Ford Pinto, and should have never been allowed to be imported into the US. They were (and still are) underpowered, and unsafe.