Evidently you refuse to believe me. What Ruger is telling you is just not true. Simple as that. Here is the story on Ruger's lock. Long and boring but it explains it. If you still don't want to believe me or Private Schultz, then go ahead and knock yourself out looking for grips.
In 2005 Ruger came out with the New Vaquero. This newer smaller version of the Vaquero had a new steel copy of the old aluminum XR3 grip frame that Ruger used on their single action revolvers from 1953 to 1962. In trying to satisfy the Cowboy Shooter crowd and emulate the Colt, they made the grip frame only 7/16" in width whereas the original XR3 aluminum frame was 1/2" in width. The new locks they had for these grip frames are wider than 7/16" so they stick out on each side of the grip frame. The locks are .480” in width.
This was no problem since they put molded black plastic grips on the New Vaqueros. They are concave in the backs so the locks did not interfere with the grips at all. However if you put a flat backed wood grip on the gun, it needed to have recesses in the backs to fit over the locks. The only guns that have this New Steel XR3 grip frame so far are the New Vaquero, the two 50th Anniversary flat tops (.357 & .44 mag), the Montado, and the now Ruger cataloged .44 special flat top. So, the only guns to have that narrow steel XR3 grip frame are either the New Vaquero or the New Flat Tops. Beware that the new flat tops say Blackhawk on the side of the gun but as I said they are flat top Blackhawks.
OK now on to the regular Blackhawks. Maybe a year or two ago Ruger installed the locks in the aluminum Blackhawk grip frames also. But they left the grip frames at 1/2" in width which is wider than the locks so any flat backed grips do not need any recesses in the backs to clear the locks.
As far as I know, so far none of the stainless grip frames have locks in them except for the stainless New XR3 as used on the New Vaquero and stainless flat tops. I have been told by customers that they called Ruger and were told that the plastic grips sold for the new blackhawks would not fit an older blackhawk because they were made for guns with locks. So even the people at Ruger (well at least the telephone sales peopl) don't know what the hell is going on since those new black plastic Blackhawk grips will fit the Blackhawks as well.
Any flat backed wood grip made to fit the regular Blackhawk XR3-RED sized grip frame will fit the new Blackhawks with the locks in the frames with no problem.
The plastic grips on the regular Blackhawks (non flattops) with locks will fit the older Blackhawks without locks with no problem.