A number of years ago when he was still with Gruhn's Guitar, I sent him an email asking him how many 20/20's he thought were manufactured. His answer was that he had only seen two & he thought around 12. The consensus here was somewhere just under 100. I regard him as one of the leading living historians on Gibson Guitars, but some of the obscure things we discuss here may be too odd for even him............... I don't see any reason why anyone would copy that guitar, it would be interesting to know who it was made for. This may be a dead end, time will tell..........