I *think* they are identical.
I recently replaced the base pin in my Gaucho (Taurus forgot to harden the original pin) and I used an aftermarket pin for Colt SAA. I had to grind 1/8" off the end of the pin for the transfer bar, but other than that it was a perfect fit.
IIRC, new Colt SAA grips usually require some minor fitting even on Colts.
I have access to a holly log. One of the largest American Holly trees in the world was at my parents' house in East Texas and it blew down in Hurricane Ike. I'm afraid they cut up and burned most of it cuz it fell on the house, but my mom says they saved me a piece and painted the ends so the wood doesn't crack. I'm trying to figure out how to make fake ivory grips for my Gaucho and my BHP with some of it.