Original invoices Dave that are printed in Fishers reference in regards Bertram Reinh that subcontracted every bit and fitting right down to scabbard screws..and the wooden shipping crates the daggers were transported in.
There are others who also have participated in blade blanks purchasing as seen on "some" other producers.
Chained SS blades are a perfect example leaving on some just a casting mark on the tangs which are identifiable.
A Late SA dagger without a RZM control number points to my reasoning also.
Regards Larry