Besides a loop of wire mounted on a little stand I also have a couple of capacitors, 0.01 uf and 0.1uf, each one with a small alligator clip on one lead, to use with my generator.
The voltage rating can be fairly low, NEVER connect to generator to the plate side of a tube. If the instructions call for a cap, or I think I need one, I clip the hot lead from the generator to one cap lead and use the clip on the cap other lead to connect to the radio.
Here is a link to the Antique Radio Forums Archives. They scanned in a book from 1947, "Elements of Radio Servicing". Of course equipment like frequency counters, dual channel oscilloscopes, etc. were uncommon or non-existent in 1947.
https://antiqueradios.com/archive.shtml
No clubs are meeting now because of the virus, but generally they are a good resource. There is a fellow in the club I'm in who presents quite a few technical talks. Sometimes the text is kept online. I don't know if he was a teacher or something. Here is one by Mike McCarty about aligning radios.
http://vrps.org/documents/Alignment.html