How about pulling them all out of the weeds. Put new batteries in all of them, pay a mechanic to come out and get them all running, then put them up for sale. Big difference in price running vs non-running.
I'm assuming some of them are still 6 V or dual 6 V for 12 V system; your probably looking at $250 in batteries on something that almost for sure needs more then a battery, for an increase in sale price of max $750 for some of that stuff? Wouldnt bother. The way I see it, there are potentially 3 tractors in the pile that would possibly be worth over $2500, As Runners (the IH-606, Farmall-A, and the IH industrial). The others wouldn't sell much above $1500, in good working order.
That's not to say, checking oil, trying to jump any 12v machines out there, and maybe they are better then they look is a bad idea, but I would certainly do that before investing in batteries, fluid changes, ect, but thats assuming it's not something you have to get moved in a limited time period.
Don't spend anything on any of them till you're sure the engine is free, they still have mostly oil in the oil pan, and the starter is intact, and clutch free. After that, you can start making an informed decision. Also, check coolant, and if dry, dump some water in to make sure the radiator or block or freeze plugs aren't dumping water. Just don't forget to add some antifreeze to anything that holds water, if they are still yours come freezing time (if it freezes more then 4 hours or so in your area).
