Confirmed by the included Colt factory letter this pistol was an experimental prototype kept by the Colt factory. The letter also confirms the caliber, barrel length, finish, and composition grips with large "C" Colt logo. The left side of the slide has the two-line model marking, two-line caliber marking on the left side of slide, and two-line Hartford address over serial number on right side of frame. Magazine absent. Consecutively numbered to the next lot.