Here's a zip archive with the relevant .STLs. There's only the right pistol grip .stl since the left grip is just a mirror copy of the right grip, which I mirrored in the slicer prior to printing it. The grip medallions are identical so you'll need to print out two of them.
I almost forgot, since I took the measurements off a stunt casting, you might need to bump the whole scale up by about 3-5%