Looks like Simson was propagated via this Russian umbrella:

>>Simson with S.A.G.(Sowietische Aktien Gesellschaft) Awtowelo stamp, Staatliche Aktiengesellschaft Awtowelo Werk vormals Simson & Co; Suhl (Thür.) from March 5th, 1947 till January 1968.<<

And Paul Jaeger looks to have been involved too:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=238521

"Special Gewehr Lauf-Stahl SG1"


Hochachtungsvoll,

Raimey
rse