There is basically nobody out there operating even a 80s combine because when you are dealing with razor thin commodities margins a couple percent efficiency in machinery applied across your whole fleet can/will make or break you.
Some boutique fruit farmer on a tiny amount of land an hour from Boston might be using an old tractor but nobody outside that sort of use case is running antiquated equipment. Not to say everyone is running locked down JD crap but old equipment isn't nearly as responsible for the contents of the supermarket as HN likes to think it is.
>As an aside, your car's warranty is essentially a scheme to make more money similar to this. Using parts of services that aren't "genuine" can void your warranty.
This was made illegal decades ago.