I might be on to something interesting here:
I have a mint double oval logo transitional Henckels 1938 NSKK. I purchased this dagger in Belgium about 25 years ago.
The dagger was at a premium price because of its condition and it included a never removed RZM tag
(the not-so-choice hanger was not included, but added by myself as it was a period piece).
The RZM tag is made of the proper paper, has the proper rivet, proper age and I have no reason to believe it was later added.
Besides, tags weren't really a hot item 25 years ago, merely "interesting"....
Next I'll speculate because I can't find any reference on this type of tag:
The interesting part for me is that the tag has no "M7/10" designation, nor a provision for the stamp.
Can my assumption be correct in that the double oval transitional logo pre-dates the twins logo from the latter '38 and '39 versions?
If that is true, then the tag might be a "transitional" design as well, where the later tags have lines for the M7 designation?
Hopefully someone can shed some light/input on this subject?!