Used Three-Piece Bass Trombone Mouthpiece - Gold Plated - Unknown Maker

Used three-piece bass trombone mouthpiece with screw rim and screw-on backbore in gold plate. The manufacturer and model are unknown as there is no stamp. The mouthpiece is in very good condition with light surface wear and a small nick on the rim but no plating loss, and some gold wear (through to the silver but not raw brass) at the insertion point on the shank. The rim is roughly a Bach 4 diameter, and the cup is closer to a Bach 1. Threads are *not* compatible with Warburton/Greg Black. 
UTB-106