I got into building wheels in my teens (1970s) and built boxes (50 or so rims/box) of Super Champions. I later got into just building for friends and weird lacings. We also made some of our own hubs esp. for tandems when 140mm was difficult to get. Last I built was just before the kids were born for the tandem. I still have my old Assos spoke wrench. I was going to build a pair for his final Nats for sentimental reasons, but 2020 kind of fell apart. If you use round spokes (don't) I have some pointers :-).
The Mercury Wheels are some of the best laced in the USA. They have builders who are W2 employees. That is rare. ax-Lightness strings them tighter than anyone @ 140kgf and the only carbon rimes I've seen that were never drilled (they mold the holes).