Good luck with it. My buddy has done a couple of older Deere dozers and one road grader. I'm always surprised at how well those old machines respond to what is really just fixing maintenance problems, bearings, hoses and such. They get parked for something simple and then nobody ever gets back to them.
On most of them the major systems are still fine.
Re: batteries, some of the old ones were set up to use parallel 12 volt batteries for more cranking amps
I used to do that, but in the last 5 years or so I can't seem to get two batteries that are electrically similar enough so that one doesn't drag the other down. That's even when buying identicals from the factory.
So I've been paying more attention to pre-heat and just using a single real good battery. No more duals.
That works surprisingly well, and sure is simpler. On my old 310 with dual 12s I alternate the batteries instead of running them in parallel. Seems to be just as good.
rScotty