Velvet Drive CR2 help needed...

[Rowglide]

I posted this in Engines/Propulsion but Props /drive makes more sense....

I have an older (some might say obsolete) velvet drive CR2 10-13 (006) transmission and though it works great and does not leak, I feel I should freshen it up while the engine is out for a rebuild.

My main question revolves around the pinion shaft but. I have read of them coming loose and that people have used castellated nuts with cotter pins to prevent this problem.
Is this a reasonable cure? Is there any special knowledge needed to perform this task ie. torque on nut before drilling shaft...
Also... does anybody know if the nut for both the pinion and output shafts are listed as 4775Q in the manual. I cannot find this part anywhere. Is it the same / superseded as the 4775L or is there another part #? 1000-149-034 is used on later model 71c 72c trans. New nuts should be used.

Thanks
Jim