Interesting discussion! I would suspect based on all the comments, there might be a whole lot of older 'customized' or 'converted' guns out there... I have one! It's a five-screw 'N' frame, 5" barrel, with the barrel stamped "45 caliber Model of 1950" on the right side, and "Smith & Wesson" on the left side. The gun is chambered in .45 Colt, and serial number 165xxx is stamped on the butt and on the crane; however, no serial number on the cylinder, on the barrel nor inside the shroud. The frame and the crane have the same assembly numbers. My factory letter indicated the gun was built as a Model of 1955 Target, in .45 ACP with a 6.5" barrel and shipped in 1956; a small number '5' is on the grip frame, noting the gun was originally chambered in .45 ACP, so it's clear it's a 'converted' gun. I thought it was a Pre-Model 26 when I first saw it, but lacking numbers on the cylinder and barrel, plus the price, proved otherwise. Despite being a bit of a maverick, it shoots OK and is a favorite due to barrel length.