Looks like a great Jacobsen. It is missing the usual battery cover and PTO handle.The battery cove is very hard to find. And so is the PTO handle and the spring clip that holds it on.
I'm leaning more to it being a 1970 atm. My 1200 doesn't have the support bracket above the PTO and it is a 1969, I know the bracket was added around 70. But if you get us the numbers on the tractor id tag and the numbers off the K301 we can find the year for you.
The decks are hard to find in decent shape, the 42" is an aluminum one and a lot of them have been repaired if you do find one. Ebay they usually list for around $250.00 in not the greatest condition. The smaller square steel decks are also hard to find. If you do find one make sure it has all the mounting hardware.
If it has been setting outside, be sure to check the gear oil in the trans. I have seen 2 so far that were full of water. the cause in these cases were a roll pin up near the shifter ball that was sheared off on one side and it allowed rain to get in the trans.
A lot of the parts are interchangeable between the Ford 100 and 120 and the Jacobsen 1000.
New Holland has a few odd ball parts left. Like the PTO clutch disk. The majority of parts you will have better luck finding through a Site sponsor or Ebay.
I will try and help with any questions or problems you may encounter. I wish I wasn't so tired right now as I am sure I am forgetting something?
Anyway Congrats on the Jac and good luck