Input shaft seal on New process 7590 transmission

[Deere John]

I have a 77 Dodge D-800 with a New Process transmission model 7590 (leaks lub ). Does anyone know if a oil seal is used on the input shaft? I've been told that some of the early NP trans did not have front seals- but not sure if that applies to the 7590 model. Lot of heavy work to remove just to find out there is no seal. Thanks