I do not think you will find 60 year old tractors, in 2071 like you do now. you can still get over the counter parts for old Farmall's Ford's ect.
The core of the tractor may last, but all the electronic gadgets still work? Will you able to get the glow plug timer relay when your 2011 Kubota, NH, or JD will not start in 2071?
The Farmall-A I had, was 60 years old when I got it. It popped a governer spring. Off the shelf from Case/IH... It only had one wire, for the kill switch. Most of the mechanicals could be fixed, welded, or remachined. Hard to do that for 60 year old electronics that have not been made for 40 years.....
I think you will find the same cars/pickups. Sure, folks have restored Model-A and Model-T Fords, 57 Chevies, '68 Hemi Cuda's. But they are simple.
In 2071, will you be able to repair the fuel injection or electronics on a 2011 Challenger, Mustang, or Camaro?
A lot of those rusty tractors behind barns will start up with a couple hours work. My Farmall-A had come out of a falling down shed, needed a head gasket, pan gasket, and a set of rings. try that on a 2011 Kubota/NH/JD/Mahindra/Yanmar/Iseki ect 60 years from now.
It would be cool if it does happen; there is a cottage industry around restoring old iron now. Look at the Farmall-Cubs, JD-LA, Ford N.
How come when people talk about "old" anything they almost always remember the great and forget the bad? How many old tractors are a pile of rust behind the barn? What percentage of them made it 40 or 50 years?
Just yesterday this late 70s Kubota
B7100 was posted on the local Craigs list. I wonder how many people looked at it new and said it will never last 30 years? Looks like it has a lot of years left in it to me. I keep thinking about calling on it, it's only about 20 miles from here but I really don't have any use for it.