Oh Dear! That's kind of tough. Depending on your skills many tools can do double or more duty. I would be lost without my buffing wheel. It takes care of rust removal and polishing of the metal, and buffing of the scales for evaluation and/or polishing. Files and a small hammer for re-scaling. Of course there are the consumables to consider as well. Golly there are a lot of tools I probably use without thinking about so I am just mentioning the ones I would not be able to continue without.
What's the color of an automobile? The tools you need kinda depend on what has to be done on the resto. Are you just polishing and honing? Are you repinning? Are you making your own scales, and if so, are you making the scale material? There are a lot of variables to the question you ask. By the way, the car's red.