Quoted from NicoVolta:

I leave nice originals alone because preservation is important. However, if they aren't nice (and a lot of them aren't) a full resto is the only way to recapture or exceed the original wow factor. Otherwise they are in danger of being forgotten or neglected as time marches on.
Personally, I prefer to turn ugly ducklings into enhanced restorations. Clear coat, stealth LED, cab repaint, tuned coils, polished metals, enhanced lighting, even subtle game logic tweaks takes everything to a whole different level of fun and amazement.
Chuck Dietch (ckcsm) in Lansdale, PA owns an automotive body shop (I visited him during my original pinball tour). He has the techniques and equipment to do INCREDIBLE cabinet repaints which greatly exceed anything Gottlieb ever did on the factory floor. Chuck's clear coated Surfer cabinet was velvety smooth and dazzling to behold... just oozed quality from every inch. I'm still envious!