I agree with technight - if you have been lucky enough to catch the caps before they leak on one of these machines, the time to replace them is now, before they leak (they will - that is a certainty for 25 year old caps) and harm the boards.

I have had much better luck with boards that have been proactively replaced (SE/30's, II's, Cx's, Ci's, Classics, Portable and and numerous powerbooks).

If you are concerned with originality of the board, replace with like caps.