Thanks John. Yes I've come across those charts and have them and I'm actually eyeballing that very set. Another slipped by me last week by a just a few minutes. I've never seen a Waltham set but did see 2-3 taps once in a estate lot that the seller thought they were miniature pin punches. They were in very rough shape. Otherwise haven't seen anything else about american thread pitch or taps and dies for that matter...still lookin.
How come? I'm kinda all over the board. Pocket watches, wrist watches, both large and small, non-working scrap missing and broken parts. I only own one vintage that was my grandfather's and I had that professionally serviced. I had no direction and just dove in. Figured out practicing on larger was easier to learn on. Just what worked for me. I don't see myself falling off the planet over these, though? I'm not a pro or a repairman. Just a hobbyist.
I have one of those and I'm happy with it. Doesn't cost a fortune, about $200+, and it will tell you a bunch of things about the state of a movement. And, even if you're not into repairing, it is very handy when collecting watches. Personally, I consider it a must have. Compare the price to how much you spend on watches!