From what I understand, the all Japanese BSS's, whether field grade or sporter, all came with SST's. As production became more and more expensive, they started using Japanese manufactured parts but assembling them in Korea. During this transition, many of the guns were assembled in Korea with SST's. Gold SST's. After a while longer and the cost of production became even more expensive, they cheapened some parts, put on plainer wood and did away with the SST.
So it is my understanding that all completely Japanese made BSS's should have a gold SST. Anything that says "Assembled in Korea, Parts Manufactured in Japan" could have an SST, or may not.
It is also my understanding that because of this chain of events, the silver triggered, Korean assembled guns were the later guns and the all Japanese guns were the earlier ones.
I do not own a BSS (although not for lack of trying) but that's just what I have heard from some people that I consider to be experts on the subject.
