if you post the #'s fromt he bellhousing aft of the starter I'll tell you the year. however.. being a diesel.. i bet you find it pitted.. many are. in the end.. if a 961 D thru and tru.. it will be a 172ci engine and be a late 58-62 model.
value wise.. year will be irrelevant... if she starts good cold, holds good oil pressure.. does not slobber excessively. restarts hot.. charges. has no mor ethan the usualy minor drip or weep, and pulls good under laod, and doesn't fog mosquitos or loose oil / water or let them mix / blow steam, and the hyds and brakes work and the PA rims adjust and aren't in need of repair.... you are looking at a 2500-3500$ machine.. or would be in my area. a region devoid of fords like that.. may command more.. as will some higher economic areas. areas glutted with fords.. or that are predominately a different color machine area.. it may value at a lower number, same with an economically depressed area.
i have seen them priced to sell and go for less, and I have seen similar priced at 4500 and sat years till they dropped over a grand to sell.
that's why it is hard to make money restoring some tractors.
you start with a machine that may cost you 1500-2500$ and put in labor and parts that may easilly total 1000$ for simply servicing it, repairing some minor cosmetics and painting it.. to more than 2500$ if it requires major cosmetics or an engine rebuild, or tranny work.
hard to take a 2500$ tractor.. put 1000$ in it.. and then sell it for 3500$ and know you made nuttin on it. or ask 5500 wanting 4500.. and then getting told it's a 3500$ machine in many markets. occasionally you will find an especially good specimin that someone just went fullout on. IE.. really did take it all apart.. replace EVERY seal and bushing and bearing and oring, shim or repalce every out of spec part till it was correct or repalced correct or remachined. same with engine and all gears. then bead blast it 100% and then do a sports car quality body job on it including baked on pro grade finish paint. new tires and fluids. esentially yeilding a good or better than when new machine. For those.. expect 8000-10000$ asking price.