Other than the RH plate, cams and pintle pad, these are ALL BA parts. Looking forward to getting this build done.
It's a common misconception. The truth is that this is just the standard back plate style, manufactured throughout WWII. It was made by Rock Island, Buffalo Arms, Border Cities Industries and (early on) even Saginaw Steering Gear. Both Bakelite panels and one-piece aluminum grip were made. Occasionally you see wood panels too. Buffalo Arms can be found both ways, as can early Saginaw and many unmarked of indeterminate manufacture. Rock Island didn't mark them. BCI I have only seen with Bakelite.I wasn't aware of a 1919 back plate with wood or plastic grips. Learn something new every day