I'm curious what the basis is for your reference to "the same Jinbao factory" and the apparent assumption that there is in fact a single Jinbao factory, and that all Jinbao instruments are made in this one factory. I've always had the impression that Jinbao is some sort of conglomerate with multiple factories and multiple sites. What have you learned about this?
Gary Merrill
Wessex EEb Bass tuba (DW 3XL or 2XL)
Mack Brass Compensating Euph (DE N106, Euph J, J9 euph)
Amati Oval Euph (DE 104, Euph J, J6 euph)
1924 Buescher 3-valve Eb tuba (with std US receiver), Kelly 25
Schiller American Heritage 7B clone bass trombone (DE LB K/K10/112/14 Lexan, Brass Ark MV50R)
1947 Olds "Standard" trombone (Olds #3)