Maybe you want to keep it all original? I don't think I'm understanding the question either.

If you want to keep it original, the obvious choice would be re-building it if it is possible at all.

If you don't know whether or not it is a good candidate to "rebuild", then when you are ready to get to it you should have someone that would know for certain take a look at it.

The only way to know would be to take it off and inspect it. At that point, if it is usable or not you can either re-build it, have someone rebuild it for you or simply toss it and get another... it'll have to be removed in any case.

Maybe a little more explanation would help us answer better??

~Angel