You need hundreds of screws for the Enigma - most of them M2, 2.3, 2.5, 2.6 and 3. All screws were turned not pressed and nickel plated afterwards. I made some sizes myself but bought the most ones. I nickel plated those too.
Making screws is not really difficult but time consuming, because you have to cut the slots after having turned them. I built a special jig to actually turn the slots in.
Nickel plating is not that hard but I had to put all screws into the drum because it had to be filled to a certain degree. This went well but I did not really enjoy sorting the 22 different kinds of screws afterwards.