Those JC Custom are made in Brasil by lathe(not by computer) in a home (I ve been told by a Pro Tuba Player in Brasil) they are not perfect as they are made by no specialist, just one guy who discovered he can make replicas of another mouthpiece numbers. I have been told that they are not good BUT they are becoming popular here in Peru by folk bands but is because:
-They are novelty (here in Peru)
-Screw rim is novelty (here in Peru)
-People seems to buy novelty as here we do not have all the brands of mouthpieces aviable in USA or Europa.
That sounds pretty close to just what joshealejo said - copies, not good - but it might be food for thought, eh? Vaguely similar situation in some other Latin American countries: ornate mouthpieces, very showy but, well what are the odds they play any better than an average Bach 18 - and what are the odds the player even cares? He can play whatever mouthpiece he wants, because he steps up to it and makes it work. He can't get a mouthpiece that can make him a great player, he has to make that happen on his own. But he can get mouthpiece that looks cool.
