It's a STI frame and a Caspian slide. The slide started out totally bald.
Parts list:
Schuemann AET barrel (clark para ramp cut)
Wilson Ambi Thumb safety
Ed Brown Grip Safety
Ed Brown slide stop
C&S Hammer
Extreme engineering sear
EGW hammer strut
EGW link
EGW Firing pin stop
Aftec extractor
Dawson fiber optic .090 wide front sight
STI bomar rear sight