Honestly man I don’t know I bought them used no paperwork how can I tell a difference
Sorry I'm late to this party. @RACHGIER is correct, these pistols are Standard Arms, and they're long out of business.
Parts from the Cobra Patriot 9 should work in the SA9 since Cobra Enterprises took over the tooling. Unfortunately, Cobra Enterprises just went of business last year, but Patriot 9 parts might be easier to find. But first try putting the spring in position on the trigger bar. There's a channel -a groove- cut into the underside of the trigger bar and the spring needs to be rotated around and positioned so that it puts tension on the trigger bar. (Never mind that the second pic illustrates the spring position on a Kel-tec P3AT, the principle is the same