metal c-clip or rubber o gasket on drive shaft?

[HORNMAN]

Hey all,
sorta new to site, have a question... I have a 96 GTI, did a shaft rebuild, all is well so far, wondering if I should go with the rubber o ring instead of the metal C-clip that prevents the stainless top hat looking devise from being pushed forward by the bellows holding the carbon ring devise... also, will zip ties suffice in lou of the okeef clamps on the rubber boot off the pto, and lastly, I was able to put approx. 3 oz. of pump oil in the cone, is that too much oil for that application (wondering about expansion room)Thanx for any feed back... Mike