On 12/04/2023 I posted:
"The maker's mark, on the blade, was hard to read and has 5 letters. The seller thought it was French made. My friend in Germany suggested it was a German made Verlangerungsmesser".
I have found another image of this makers mark on a dagger also said to be French by the seller, with maker's mark: ERBER.
See 1998 edition of GOINS, page 92: ERBER GERMANY.
My friend in Germany was correct, the Verlangerungsmeeser sold for $465.00 was made in Germany.