Recently I picked up a Girsan MC P35 the California version with the optic plate and loaded chamber indicator. (Which I hate btw) Anyway I was looking for another upper assembly one so that I could have one slide assembly with an optic and one with just standard irons and after getting nowhere with Girsan I found a nice parts kit that included everything but the frame. Well I can say with certainty that the Girsan is a direct copy of the MKIII Browning. I started swapping parts just to see what is a direct replacement and can happily report that everything is. Currently I am just using the complete Browning slide, barrel, guide rod, sear, sear spring, thumb safety, ejector, magazine release a C&S no bite ring hammer and some Springfield Armory wood grips and I have had no issues dropping those parts in. I may replace the trigger assembly with the browning parts just out of curiosity but i believe they will work just fine. Girsan did a good job of copying the MKIII design.