Yes, the late Ronnie Burke was the author of that fine book. If I am understanding your question about the ST designation correctly, the “T” was never dropped when they “added the integral scope base”. The Ruger integral scope ring base system was the original design offered as a R or RS rifle in the first generation of M77 rifles when introduced in 1968. The D&T “round top” receivers were offered a couple years later by Ruger at the behest of some gun writer friends of Bill’s so they could use their favorite scope mounts of the day and satisfy the sportsman who had the same attitude. I personally have never understood what the ST & PL designations were suppose to mean? I’ve even seen photos of an ST rifle with a box marked “RT”, meaning round top? I just don’t know
