Close the fuel system bleeder and crank it. If it still doesn't start, loosen the line at the injectors (one at a time), and crank it until you see fuel come out. Tighten the line, and and then repeat with the next injector.
Let us know how that goes.
I had a friend who had a Ford 8n with the same problem. He started it in high gear (fast), went high throttle and stomped on the brakes. it freed up after a few tries. Having it in 4wd is a good idea.
2800 hours is barely middle aged. I agree fresh fuel, turn the key on, and jump across the solenoid/starter. If it starts and runs, you have a real deal there.
WEIGHT is the most important consideration. Generally, it's worth paying for a heavier frame, and larger diameter discs. A 5 1/2' width would be the bare minimum. 6 1/2' would be my choice for your size tractor.