[So.Cal.Super]

I have a neighbor who has a rebuilt t400 with shift kit and new reman converter. it was built I want to say 2 years ago and has sat with only the assembly lube in it. anyone know or have experiance with something like this. can I just add fluid and be good? should the seals be checked? he wants $400. for it and it sounds like a good deal. mine will need a rebuild soon and I know it will cost more.