The Model 72A had some re-built parts, notably a solid lifter; the prior 1 was split. Model 72s had no pull-weight adjustment screw as is found on the 69As. With all the Significant Wall Variation, built for the more impressive cartridges, just the top in the breech block is seen https://highimpactrounds.com/product/winchester-super-target-12ga-2-75in-1-1-8-oz-8-shotshell-1145-fps-25-rd-box/