For a working gun a cowboy will almost always choose rubber grips. A cowboy's job is mostly hard physical labor with wood and metal building materials. It is preferable to bounce the butt of your gun off of a metal fencepost or gate with rubber grips over fancy grips.
I've been a cowboy damn near all my life. I don't care what Texas Rangers or Elmer Kieth, law enforcement, like. Don't care what John Wayne, an actor, likes.
Cowboys are still out there today. I know a lot of them. The guy passing you on a curve in Raton Pass who is driving a 30-year-old Buick with a spit jar between his legs and towing a two-horse trailer is probably packing a Hi Power. In terms of his personal possessions it ranks right up there with his saddle and his horse. He probably paid about the same for all three and it was probably all he could save in a year.
He's more likely to spend $100 on a new bit than to spend $50 on grips.
Sorry guys, but I've done a lot of cowboying and I must have been darn near 30 before I figured out a Colt SAA could have anything but rubber grips.
My daily wear gun still has rubber grips.
My barbecue gun, well, that's another story...