In that era, of course you will always see small differences in the same design as built by different manufacturers. It was obviously before the improved machining capabilities that were developed during the war years (both wars), and 85+ years before the CNC machining we know today began to appear. Short of military involvement in the manufacturing process, you would have always seen dimensional differences, just as you would have seen improvements and adaptations of any shared design, over time. That is only to be expected. When I say 'same gun', I'm obviously speaking generically. I intended to make it clear I was referring to the same basic design...different manufacturers working off the same patent, adding their unique touches. So, of course, you would never expect to be able to swap every part between different manufacturers' models. Of course, one manufacturer might decide to make a tang longer or shorter, thinner or fatter. Of course barrel dimensions might be different enough that they would not interchange between manufacturers. Of course spring arrangements might be slightly different. Because, of course, each manufacturer would want it's own signature on a shared design to differentiate it just a bit from the other guys' and also to make the gun's manufacturing process fit the capabilities of their own individual physical plant as best as possible. But, then again, typically you could not buy parts from the same manufacturer and expect them to fit without some time spent fitting them. Final hand fitting was the rule, not the exception, in those years.