I finally got it all back together and now that I have the engine rebuilt I'd like to adress the hour meter. The tachometer works but the hour meter doesn't. Is that something that can be repaired or is it just something you replace?
As you'll be aware no parts are listed through JD so it's a replacement item. Common item across a range of models of the day.
On that basis, you have nothing to lose trying to fix it. It's cable driven so the tumblers will be geared and you may have a stripped gear? Cable must be ok if the tacho side works.
Alternatively a specialist instrument repair shop may help. Google is your friend here.