What a coincidence. My first centerfire was a Ruger Security Six, SS w/ 4" barrel and I put Herrett grips on it. That was about 1975! I also started my reloading life with it.
I just recently Karma'd the original grips here. I didn't figure to be buying another one.
I loved that gun and it was the most accurate handgun of any that I remember owning.
Unfortunately, it was stolen around 1981-82.