I think they are "interesting", some folks feel that the interchangeable lens mounting system was designed by the Devil himself....
The 1.9 /50 Cintagon was the "fast 50" for the C-44, and was indeed made for Argus by Steinheil... the standard lens was the f: 2.8 / 50 coated Cintagon, which was American-made - so far I have not found a serial number on the American lenses.
The C-44 is a decent performer, and quite a bit closer to a high-end rangefinder than the C-3 or A Argii, offering a rangefinder that is integrated with the viewfinder, and a system of interchangeable lenses and accessory finders.
Like other Argus products, it offered good performance at a modest price.
Regards,
LF