New memeber's challenges

Hello everyone,
I live in a suburb of Los Angeles, but am finally lucky enough to have attained my dream property. It is 3.6 acres of abandoned lemon orchard, and an early 1930's galvanized, corrugated metal and red wood posted barn, only 1/4 mile from my house. Water is impossibly expensive here, so I will fill the barn with my collectibles, and use the acreage as a refuge.
I have spent much of my last six months digging with pick and shovel, and occasionally a big jack hammer, to excavate a 20' x 32' extension area to add to my barn. The last month has been especially challenging because I discovered the huge trunk, taproots and collateral roots running up to 4 feet underground on about half the area, and have had to meticulously chase them all out before risking casting a slab over a likely mini cave in site.

At first all this effort seemed recreational, and good exercise, but by now I have learned that I need to work smarter in the future.
Accordingly I just visited the owner of a 1950's Massey Ferguson tractor with a bucket and drag box that I found sitting on at least half flat tires off the end of a dirt road in the woods. I first walked past it about 5 years ago and it has not budged for an equal amount of time before or since.

He said that it came with his house, but he had all the hydraulics rebuilt, and tires replaced 10 years ago, but never used it, because it somehow got delivered with one of the rear tires flat. Coincidently, a friend had stopped by just a couple of weeks earlier, hooked up a battery, and got it to crank over but not start.
What voltage batteries do these use?
It has been sitting ion shade- what condition do you suppose that the hydraulics would be in at the present time?

He doesn't know his price yet- what is fair for it in as found, non running condition?

I am also trying to revive a 1970's Ditch Witch that I got missing its Wisconsin AENLD (?) motor with 2/1 reduction gearbox and clutch(s) and 4" pulley.
Any suggestions?