I have worked on all of these frames while working for Les, in the Company's early years.
The frame on the left is a Caspian single stack 1911 frame. They are unique in that they have a cast-in plunger tube.
The rusty one is a Para frame. So is the Officer's Model next to it.
The Para's were tough to checker, I ran into a lot of pits. The Caspian's were real sweethearts.