I've gotten help on other forums and not trolled in rebuilding a Dewalt radial arm saw from the 50's that was built like a tank. Never got a response "what do you expect from a 68 yr old saw". It needed bearings and the members there gave me NAPA part numbers. It came apart and went back together with no problems. Beautiful machine.
Same thing with a 67 yr old Choremaster chain saw. Picked it up at a flea market and resurrected that, too. Came apart, and everything was serviceable down to the points. Members supplied parts schematics for the repairs.
This cylinder was nowhere as old, and what difference does it make how old a serviceable part is if you can't get to the parts that are expected wear out?
I had limited time to work on this tractor. The bucket cylinders were serviceable and allotted the same time, budget, and brought south only the tools needed from the previous experience for this job. It's an easy job.
I would expect this tractor to run another 30 years as many of it's predecessors from other manufacturers as long as parts can be replaced as they expectedly wear out.
The tractor is not run hard nor used every day. My daily drive is a jeep a few years older - this ain't my only rodeo.
The advice I got from some here was taken. I got cylinders that have steel gland nuts and will be serviceable in the future.