And already back again.
Checking up on the Ulrich "Kühm" title mentioned above, I found this library entry here in the online catalogue of the University of Hamburg:
"Inschriften und Verzierungen auf Richtschwertern; ihre Deutung aus der Person des Scharfrichters" by Ulrich Kühn, 1969.
https://hhas21.rrz.uni-hamburg.de/DB...ichtschwertern
a.) The last name of the author is KÜHN, not Kühm.
b.) Apparently he wrote his doctoral thesis (158 pages) about this topic before publishing the catalogue mentioned above - might be easier to locate for you.
And if you understand German - yes, one of the two editions in our libraries here is basically available, but currently someone else has made a reservation for it... and yes, that´s me

I will get it on Monday.
Maybe contact me privately via my adress in my profile.