Safari Arms Info?

I recently purchased two different Safari Arms pistols, and I'm trying to get an idea of when they were made and their actual model names or numbers. The first is a Safari Arms 5" barrel 1911 made in Phoenix (so it's original SA and not the stuff made after Olympic bought them out). It doesn't have any Matchmaster branding or markings on it, and I'm thinking it might be a Model 1981. It also has the adjustable Smith & Wesson K model rear sight. The serial number is in the 5xxx range.

The second is a 6" Safari Arms made by Olympic. It was messed with a bit before I got it (I think someone was trying to make it look like an AMT based on what was done), and it's got an S5XX serial number (so I think it might be reasonably early production). Since it's stainless steel I think it might be the 6" Matchmaster instead of the Big Duce, but don't know for sure. Of course the people I bought both guns from really don't know much about them, either.

Any information would be greatly appreciated. These pistols are hard to research, based on both the buyout by Olympic and the fire they suffered that took out almost all their records.