Would believe Smith and Wesson? Read it in American Handgunner!
My mistake... er.. sort of.
According to this 1997 Oct. issue Pg.96 of Guns And Ammo TestFire, McCormick, supplies the sights, the grip safety, the hammer, the trigger and the sear. The frame and the slide come from a common vendor Jericho Precision of Yonkers, New York.
Jericho supplies the frames and slides for such customers as Kimber, and such customsmiths as McCormick, Wilson Combat and Nowlin Manufacturing. The article goes on to say on pg. 97 that Kimber had just acquired Jericho's manufacturing operation and they would continue to supply the slides and frames to those firms who had previously had been purchasing from Jericho.
This aticle was written by Jan Libourel of Guns& Ammo. Maybe someone has something more recent.