There is a difference between a mild cleaning of a decent case, gun, or old car, and a complete refurbishing of a wreck!
Sure we would all love to find originals that are pristine, with perfect case, engines, or bores, but the truth is, most of us can't afford them.
An original that is well maintained, or slightly used, but not abused will be worth many times what a completely restored cartridge, furniture, car or gun will be.
I'd much rather have the original in used, but not abused condition, in every instance.