I believe it was bought by Remington (or whoever owned Remington) a while back. Not sure if it's 100% gone or filed away for later.
I had a Sig Blackwater over a decade ago. It was Sig's answer to the Kimber TLE/RL and comparable models. Shot very well, and I really liked it, but I never did get a holster for it. Sig's external extractors are arguably (or at least Sig will tell you) better than the old internal extractors - I certainly never had an issue.Biggest complaint I remember from back in the day was SIG's use of a rather blocky slide that sort of looked like a P22X. This complicated holster selection.
Side note: Sig dropped the Blackwater name and re-labeled it the TacOps. It was 100% identical other than the name. If you have a Blackwater, it might have a small bit of collector value.