That would not be a 27. Model numbers were not assigned until 1957. In 1955 (estimating yours at Feb. - March 1955) this model was simply called "The 357 Magnum" as it was their only one at that time.
That is amazing. I had no idea it was a pre 27. Thank you very much friends. I too will get THE book one of these days. I used to read a book I believe the Complete Book of Shooting. In it it had all the models of Colt and Smith and fell in love with the Colt Commander pics and would mull over all the SW models. I already had experience with my dads guns, shooting at the San Fernando Gun Club in Newhall cal. It was a different world back then Newhall was out in the sticks. We always had Smiths and my dad would wear the 357 while we were mining in Lucerne or vacationing in Trinity cal. Jeff Cooper had a section in the back of that book. Old days style but all business. Im mostly a revolver shooter but Ill shoot what is in my hand. My first gun purchase was a Combat Commander in .45. the latest a mod 14 8 3/8. Coming to this forum is like being a kid back home.....H