When you state "for throttle levers" I'm assuming you (and Digi-Key's description) mean the CH Throttle Quadrant?
I just ordered a REPPOT615 for my CH Pro Throttle and it doesn't work. Not a big deal but just wanting to clarify for others.
See attached image, Pot on the left is the original in my CH Pro Throttle, note the long shaft. Pot on the right is the REPPOT615 received from Digi-Key.
Looking on Digi-Key's website I would have to guess, going by pictures, that the REPPOT604 is for the CH Pro Throttle as it appears to have a longer shaft than the 615 or 632. Link:
https://www.digikey.com/product-detail/en/ch-products/REPPOT604/1040-1164-ND/9490875