I can relate to that!
Been trying to be more aggressive with my preventive maintenance. Like the tires on that haybine -- both hold air and might run for another 10 years. BUT the sidewalls are cracked bad and while airing them up I was leaning way back, off to the side, and squinting at the gauge with my head turned . . . Normally I'd just run them till they give out, but yesterday I ordered a couple of tires online that should arrive Monday.
It's getting harder all the time to roll around in the dirt and gravel to fix breakdowns -- and to scramble for parts and repairs on weekends and late afternoons. Plus everything's just going to be more expensive later. Well worth it if it prevents one tire change out in the field!