Don's right, the thumbholes don't interchange w/ pistol grip standards. Your only alternative that I'm aware of is a Mark henegar custom and rthink he's booked pretty solid but don't know. I've had two of his pass through my hands, they are worth the money, imho. Start out about $225 for a pistol grip and $300 for a thumbhole if I recall right and it's been a year or three. They show up on Excal Trading Post once in a while.