I guess it's gas per your comment. Hours and condition will show up on the steering arm(s) ball joints....if loose and you can rock the shaft easily with your hand.
Pedals show hours easily. If the buttons are all worn off and if sheetmetal pedal surface like my 3000 is worn through it speaks of 5000+ hrs.
How fast will it light off when you hit the starter? Good compression and it'll light right off. If you have to crank on it, especially a diesel, worn rings, or if you need ether to get it started the first of April in Texas, rings are shot.
If you hear knocking sounds from the lower engine it means mains and inserts...overhaul,
If you have a lot of blowby from the crankcase ventilating tube, worn rings. Diesels will usually black smoke a little especially if you ram the throttle to max from idle. White smoke is water of some sort in the combustion chamber and blue is burning oil. On a cold day a diesel will slobber some with the white smoke until everything gets hot enough to burn off the internal condensation.
Brakes aren't that big of a deal if worn.
Check radiator for corrosion in the tubes and color of coolant.
I answered how to check the clutch earlier this evening...check for a post entered a few minutes ago about a guy wanting to test clutch at a dealer.
Most Fords aren't synchronized shift, but at idle you should be able to go through all the gears with ease. If RPMs are up when you try to shift, expect grinding to occur until the drive and new driven gear get in sync and mesh. Once in gear, it should stay there, not pop out.
PTO should follow the lever. Would be nice to have an implement to drive and test functionality.
Hydraulic 3 pt should come up smoothly and speed is RPM dependent. At 1800 rpm it should make the full range in about 5ish seconds. Having a load on it would really help to test it. It would be nice to be able to have that load so you can raise the lift and shut off the tractor to see if the seal in the lift cylinder is adequate...a pain to lift the top off the hyd-diff section to get at the lift piston.
Power assisted steering should be smooth and easy to turn.
Front end should be solid if taken out on the road and run through highest gear. Any shimmy means bad alignment, no biggie, or worn members.
Jacking up the front end at the axle and watching the king pins for movement when the weight comes off the tire....shouldn't be any slop....usually have problems getting them apart if in need of repair as the pin develops ridges and doesn't want to come out of the retainer.
Expect to have some minor leaks.
I guess that about does it.