Not a clue on the cross compatibility of bevel gears from one model to another, however if it is any consolation.... I have felt your pain.
A few years back my RCK60-24B gear box took a catastrophic dump. looked into completely overhauling the gear box. I got some sage advice from this very site in how to make the decision of repair or bite the bullet and just get a new assembly.
After pricing the gears, bearings, oil seals and shims plus the cost of a qualified machine shop to set the lash on the the mating gears.... I was knocking on the door of a new assembly.
I went with the new assembly based on the reasons mentioned above, plus I plan on keeping the tractor and for what I got with the new box. It arrived complete with the belt pulley factory installed.
1000 hours later still runs like a Timex watch.
PS... the ole gal has 2510 hours on her as of Jan 22, 2022