Agreed, to each their own, but I wouldn't paint plastic. (Metal covers are another thing, again if originality is important you'd want to research methods that provide the most accurate results).
I tried peroxide, it works, but the piece slowly re-yellowed, and there are risks involved. Clear-coating presents the same issues as painting and will not provide a "factory" appearance, so no thanks. Typically clearcoats have at least some minor amount of permeability, so I'm not entirely convinced you can't still have a return of yellowing (and now you have a mess).
Dyeing solves all the problems, it leaves the original surface texture of the plastic intact and (assuming a good color match) will render the plastic looking new, indefinitely. It's the most expensive option though, plus you need an un-yellowed sample for color matching (and an air compressor, spray gun, respirator, etc). Practice on some junk plastic first...
I'd rather have original yellowed plastic than something painted or "retro-brighted", but that's just me.
