This Three Screw Ruger Flat Top 44 mag shipped in 1958. Those are the original grips, I would not dream of replacing them. You will notice the finish of the grip frame is not the same as the rest of the revolver because the grip frame is aluminum, and has an anodized coating. Ruger was using aluminum grip frames for many years, it was only with the Vaqueros that came out in 1993 that Ruger put a steel grip frame on both their blued Vaqueros and Stainless Vaqueros. As a mater of fact when I picked up my first Vaquero around the year 2000 I immediately noticed the difference in weight because of the steel grip frame, vs my old Blackhawk that I bought in 1975 with its aluminum grip frame. By the way, I would never dream of sending this one back to the factory for the 'upgrade', which usually results in a stiffer trigger pull. Leave it alone and treat it just like a Colt, load one, skip one, load four more, bring the hammer to full cock and let it down carefully on an empty chamber.
Here is the 44 Mag Flat Top paired with my old 45 Colt Blackhwk that I bought brand-spanky new in 1975. Notice two pins instead of three screws, and of course it has a transfer bar.
Here is my old 45 Colt Blackhawk and the first Vaquero I bought, also chambered for 45 Colt, back around 2000.
Now, let's talk about Bisleys for a moment. This is a real 1st Gen Bisley Colt, it shipped in 1909. It is still wearing its original hard rubber grips. Notice the shape of the grip, how it curls far forward. Notice the trigger is almost all the way back in the trigger guard.
This is Ruger's version of the Bisley grip. Notice it does not curl as far forward as a Colt Bisley grip does, it is much more straight up and down than a real Bisley.
I bought a Ruger 'Bisley' revolver a bunch of years ago when I was starting to shoot Black Powder. I had been told I would need the extra long grip to hang onto it with the stout recoil that full house Black Powder cartridges generate. I brought it to exactly one CAS match, decided I did not need the extra long grip, and sold it. I put the money down on my first Colt, with a plowhandle grip, and have been shooting Black Powder in regular 2nd Gen Colts ever since.