There are, however, also horns, particularly the “M” series models that have strong indications of being partially or completely assembled by Monke in Germany. While a few even have distinctive Monke valve casings, most still show the same stylized Bach turning. What is interesting is that Blessing valves, Blessing posts, two different styles of valve cap, and many other elements appear mixed-in randomly from horn to horn on these otherwise strongly Monke horns. It is possible that some were stencil and some were built in New York from parts – but equally plausible that Muck was shipping Blessing and Bach parts to Germany for their supplier to use, preserving both the look, and the random hand-built feel, of their product.
I'm not sure where the connection with Monke comes from, I can't find any indication. On the web page I made about Ernst Modl, https://brasspedia.com/index.php?title=Ernst_Modl_brass_instruments#Rudy_M.C3.BCck I tried to fit the Rudy Muck M series into the Emo-production, in terms of details and in terms of serial numbers.
Let me know what you think....