EK1 Wächtler & Lange screw back unmarked types in mint condition ( very hard to find )

EK1 Wächtler & Lange screw back unmarked types in mint condition

this piece is perhaps one of the most difficult pieces to obtain.
In this case, don’t be fooled by the fact that this is an unmarked piece, since the screw solutions are rarer, since they were not produced in large numbers, moreover, it is not marked. Presumably, it was not marked by accident, since almost all the specimens that have been found are marked, and in addition, their condition is perfect.
During the time I spent collecting, he only saw 2 pieces, of the SB type. This piece is one of a very rare variant.