Thanks, I look forward to whatever you find out.
Regarding the tolerances and fit, I was reading the other day about Germany's adoption of guidelines for standardization in the machinery and machine tool industry, prior to 1917 much of German industry lacked common standards for parts and units, measurements and dimensions. There were exceptions of course, structural steel, sheets and wire were standardized in the 1870's, pipes in the 1880s and railroad equipment early on as well for obvious reasons (necessity and few manufacturers). While the article was more about the machinery and machine tool industries, it is of interest because it speaks to the German War Ministry (arms and ammunition) as the organization that pushed the initiative and that even after the war the German government pursued the idea. While the article doesn't revolve around small arms or ammunition, it shows the problems Germany had with its guilds and small manufacturers who resisted changes (tradition and expense of standardization caused considerable resistance).
It is also interesting because it gives a view to why it took so long for Germany to achieve interchangeable parts manufacture, which Germany never fully achieved in small arms (it was much better after WWI than before and during). Germany easily could have achieved this standard, they were the innovators of so many industrial achievements, by the 1890s on par, more or less, with England and the US in most fields and in some fields leaders (electrical & chemical, they also introduced the metric screw thread yet had 10 different thread systems and 274 different kinds prior to the changes)- but they lagged on mass production due in part to this resistance to standardize. While tradition played a part, it was obviously the lost war that was the main impediment to creating interchangeable parts manufacture in Germany, something easy for the Czechs to tackle as they had to buy new machinery to modernize and expand anyway. Even after Versailles, Germany had an arms industry with tremendous over capacity and no legal outlet, hardly an inducement to large scale investment for new machinery, - at least before 1933.
Anyway, while boring to the collector, I find these types of subjects a fascinating look into behind the scene problems related to small arms manufacture.