I removed the pedals of a Göricke bike from 1934 or 1935 (according to the bike number). It has a Glockenlager (What is that in English? Bell shaped bottom bracket?) as seen in the picture. The crank threading for the pedals however is quite messed up and I would like to re-cut it. I measured 4 threads at about 4,8mm (or 4,9mm) with an 14,2mm external diameter on the pedals. The diameter is a tipical 9/16 pedal threading, but the thread steapness only results in about 20-21 threads per inch, and not 24. 24 is the normal amount of threads per inch for pedals.
EDIT: I noticed 20 tpi is normal and not 24 tpi. Therefore it should be a normal threading.
Is this some other threading they used in these days or shall I just cut it with a normal pedal thread cutter? The pedal make is K&B (the logo is in a cloveleaf)