Welcome! Nice first game... Great advice here so far. Still transitioning from "new" status (feels that way at least) and currently restoring my 3rd machine. I do think the answer depends on how many pins you plan to own and whether or not you plan to shop, restore, or just play. If you are in it to win it, a couple things pop into my head (some of these aren't really for a "toolbox"):
- A hex drill bit extender is super handy (lots of hard to reach areas)
- Also, I hate myself for not currently owning/making a rotisserie (again, depends on how many games & what you plan to do with them)
Off-topic, but a work space separate from your gameroom is really nice if you have that option: workbench, drawer system for parts, etc. I have a workbench for soldering and small jobs but do a lot of work in my gameroom, which leads to parts everywhere.