[Chad Hauris]

This may be a little bit of a bone of contention for me but the equipment I mostly work with is in kind of a different situation.
We generally replace all paper and electrolytic caps and selenium diodes in tube type equipment...you will have problems crop up eventually with these old caps/rectifiers if you don't.

Some of our tube type equipment really still works hard for its living doing 12 hr. or more a day constant service such as our jukeboxes and PA amps...replacing all those old components keeps this industrial/commercial equipment performing like it ought to. We want to give the same kind of reliability to our clients when refurbishing old equipment so they can use it as much as they want without having to "baby" it.

The cost of caps is insignificant to just go ahead and recap the equipment completely while you have it disassembled on the bench as opposed to having call backs because of problems cropping up due to flaky old components. Much of the tube-type equipment we work on is not collectors items but units going back into a real "working life" so reliability is paramount.
Even if the equipment is only used occasionally, replacing old caps and rectifiers ensures that there will not be anymore degradation of the old parts causing more problems.