I’ve tracked down the last tractor my grandmother sold from their estate before she passed. It’s a 1974 Ford 4000 3 cylinder gas. My grandfather had bought it new so it has a bit of sentimental value to me. It’s been well taken care of and rebuilt 10 years ago so I’m told. The farmer doesn’t want to out right sell it back to me but might be open to a trade. I have a 1976 Case 1070 power shift in relatively good condition. I couldn’t tell you the hours on either of the tractors as the meters are broke. Who would be getting the raw deal if the trade were to happen? Does the Case match up value to the 4000? Been researching tractors for sale and the price seems to be pretty close on both. Thoughts?

You didn't specify what kind of advice so here's mine:
Don't get sentimental over an inanimate object. A 4000 is a very common tractor so find another one.
I was given my first tractor - a 2N Ford, nearly 20 years ago when my father died.
As I learned more about these tractors and wanted more features, etc I sold it and upgraded.
My dad was not sentimental. If he could see how I've parlayed his old N into the tractors I have and the knowledge I've gained he would be proud of me.
And if you Gave me his tractor back I would just sell it again.

Though the Case has the capability of doing a lot more, the reality is that for every potential buyer for a 1070 Case, there are probably 10 potential buyers for a Ford 4000. So finding the buyer for the Case is difficult.

I like my 4000 Fords but if I were trading a 110 hp 1070 Case for a 50 hp 4000 Ford I'd be asking for some boot, like a couple thousand or more.

If he is sold on the 4000 as the ideal tractor for him, you could sell your Case outright, purchase another 4000 gas in similar condition and trade him Ford for Ford. You would have your grandfathers tractor, and he would have the same make and model.