used arb locker question

so i just picked up a used arb locker for my d-30 30 spline. it looks to be in good shape but i wanted to see if theres anything i should replace or look out for before having it installed. got the cost of these parts, and a good place to get them

Might as well go ahead and replace the o-rings in the locking collar and the one at the bulkhead. Check the brass tube on the collar as well to make sure it doesn't have any holes or the brazing at the junction isn't broken. Other than that, I think the locker internally should be fine if the PO didn't mention anything else.