Picked up this left feed (likely 1989) Mac 1 Annihilator along with a couple others from Gaston Nogues, today.
Gaston was childhood friends with Aaron Christopher, an employee at Carter Machine in the early (or mid?) 90s and purchased several paintguns through him.
Gaston told me how he and a few other neighborhood kids received PGs or PGPs for christmas in the mids to late 80s and eventually had them converted into Annihilators.
Looking at the Annihilator you can see the flat edges on the sides of the trigger (might not be visible in this picture) and the unmarked lower tube (no PMI or sheridan markings). These are indications of an early PG.
This Mac 1 Annihilator is a MK1 version built after Mac 1 and South Bay Arms split ways. The machining on the brass was likely done by the next shop Tim McMurray used after South Bay Arms, A+ machining.
Another couple interesting touches to this annihilator are what looks like a brass hammer, the RVA is either plugged or has a piece of paint on the back, likely indicating field legal velocity.
Other additions are the AT stops on the pump rod and the sliding UMB stock (I prefer assault line stocks).