With so many different brands of new, Asian-made bass saxophones currently on the market, some people might be surprised to find out that there are only 2 companies that make all these horns.

Jinbao
Jinbao
(Helen) Jinbao is the company whose factory makes the Selmer S80 copy under variety of stencil names including: IW 661, Oleg, Hunter, et.al. Jinbao also sell bass saxophones under its own name.
Jinyin
Jinyin
(Helen) Jinyin is the company whose factory makes the current crop of new, modern, vintage American-style basses. They are sold to many different companies, and carry many different names including the ones I've managed to find here.