Dang man. This is really sad to hear. I cant imagine how you must feel. If it helps, Maybe get some more quotes on the roofs. I wish I could contact the people I had do my metal roof a year or two ago. I had quotes to do the roof on my house and garage with asphalt. Then got in touch with this mennonite group that came and ripped the singles off, replaced rotted sheeting, and then new metal roofing on the house. On the garage they put furring strips down and metal roofed over the existing roof. Did it in about 5 hours time. Cost me less than the quotes for asphalt.
I wish I was in the market for a tractor still and could help you out. Best of luck man. I would find many other things to sell then the tractor but i dont know your situation either.