I heard back from Gary. The LP needle is marked SA100 and the 78 needle is marked SA250. I guess that is a micron measurement or something similar?
Thanks for the tip about soldering the connectors on first. I'll try using a vise to keep the small parts steady. I'd like to have this done by tomorrow. The only remaining job is replacing the selenium rectifier, and possibly rewiring the power to switch/fuse the hot side as per the suggestions here. Along those lines, my dad asked me yesterday if I am supposed to use a 3-prong earth grounded line, and I told him I didn't think so since I would have to tie the neutral and ground wires together (from what I can tell anyway since the chassis functions as the ground), and that would cause problems if an outlet was wired backwards in any case. Is that correct?

Correct. A major redesign would be required to use a three wire power cord.