Three companies were asked to submit designs : Metall und Lackierwarenfabrik Johannes Großfuß AG of Döbeln , Rheinmetall-Borsig of Sömmerda , and Stübgen of Erfurt .
These were : Metall und Lackierwarenfabrik Johannes Großfuß AG , Rheinmetall-Borsig , and Stübgen .