Grand daddy's old ford tractor

I have cut, raked and bailed hay on this tractor when I was about 10-17. Left for the Marine Corp and after a tour in Iraq I came home to my granddaddy who passed away the next year! He left me that tractor and now I'm trying to get it back running! Starter is bad, ignition switch is bad due to some punk putting glue in it, need all new oils , new battery and new tubes in the tires. I thought I'd start with the year and I have no way of knowing this . Here is what I can read:
Engine 501325 or4. OH29
Model da 214c
Unit 0j02b
Block serial # D301324
Block stamp # D5NN 6015 G
Can anyone help ? Thank you in advance.
Edit ; I do know that it is a ford 4600 , says that right there on the side.

Welcome. here's some information on the numbers you found on your grand daddy's tractor:

Model da214c- The DA2 at the beginning says that it is what was called a model 4600 tractor with an all purpose agricultural chassis. The 1 in the 4th spot says that it has a diesel engine. The 4 in the next spot says that it has independent 540 rpm PTO, and the C at the end means that it has the 8 spped transmission (4 forward gears and one reverse on the main shifter plus a high and low on the range shifter for a total of 8 forward and 2 reverse gears.

Unit 0j02b - This tells us when it it left the assembly line. The first 0 means that it was made in a year that ended in a zero, and since the 4600 was only made from 1975-1981, the only year that fits is 1980. The J means that it was made in September, the 02 means that it was made on the 2nd day of the month, and the B at the end tells us it was made during the day shift, so your tractor left the assembly line on September 2, 1980 during the day shift.

The casting number on the engine block, D5NN 6015 G, is a 201 cubic inch 3 cylinder diesel engine, which is the correct engine for a 4600 tractor.

Bobandcoconut, first, I'm sorry for your loss of your granddaddy, second, thank you for your service to our great country The United States of America and third, good luck bringing your tractor back to life. It may seem like work at first but you'll find it very rewarding to get granddad's tractor running again.
Make sure you have a fully charged battery with new clean battery cables, very important with diesel engines. Replace all fluids as necessary. Once you get it started you should be able to make more decisions on any other repairs. Find the shop manual your grandad probably had or order one to help you fix any problems you come across