Various early MP5 prototypes

[some_kid6]

Found on Reddit:





H&K MP5 SD tool room prototype: The QD thing is interesting. Looks like a toothed gear system to an interrupted thread




H&K MP64 (MP5) Serial number 3:




H&K MP5K Serial Number 1:

 

[Scsmith42]

Interesting pix, thanks for sharing.

The trigger housings in the pix appear to be newer versions than the metal originals though.