The 190M is associated with the tubeset & is an Sauer inhouse number or an assembly number. Lindner also had a similar number but it did not end w/ a letter.




Even though the subject example is also devoid of the Large & Small Crowns along with Nicht Fr Kugel & load data, here is the Large & Small Crown thread:
http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=172178&page=all


http://www.doublegunshop.com/forums/ubbt...e6172d7d6ab57c4
Nr. 60177 thread

Cheers,

Raimey
rse