I won a 26 year old NAD amp on ebay which appears to be in great condition. My question is, although it's fully functional, is it likely that the components (and consequently the sound) could still be compromised by age/neglect? Could improvements be significant enough to justify restoration costs (ie re soldering or replacing caps, electrolytics etc)...or should I be satisfied with a functioning amp showing no obvious signs of deterioration or damage? Does "If it ain't broke, don't fix it" apply to vintage amps or is periodical work required to help the amp perform optimally? The model is NAD 3020i.