Another 2 days in the workshop. Heaven.
I had made a worm drive and gear using an M14 x 2 tap, but it did not look the part, despite being functional. The problem was that the threads were sharp triangular and they did not look correct.
So I made a worm drive and gear using Acme specifications. The teeth have a chunkier squarish look. More authentic.
I ground a lathe cutter and used it to make the worm drive in gunmetal, and another identical thread in 14mm silver steel (drill rod). The steel thread had cutting edges formed, and when finished it was hardened by heating red hot and quenching. After hardening, a file would not mark it. I did not bother to anneal it, since it would be used only to cut cut brass or gunmetal. The hardened tool was used to make a gear in gunmetal. Unfortunately I did not take pictures of those steps.
It is looking interesting, Yes? And there are 3 spare handwheels. The rest of the reversing mechanism components were made several months ago. Almost ready to install them.