I'm coming to this late, but find this an interesting topic. Refinish, repair, restore, preserve; they're all relevant but the choice seems to be highly dependent on the article at hand. It seems there are no hard and fast rules.
As in the original post, most anything with verifiable history attached to it is usually worth more in original condition, with the apparent exception of cars and possibly artwork by known masters, in which restoration is not only acceptable but desirable. A '50s vintage Ferrari race car that is totally trashed but driven by Surtees is restoration fodder and of little interest in its current condition.
The comments on refinishing, restoration and preservation all make sense, but the choice is often difficult.
A vintage Martin guitar will almost always lose value if you do ANYTHING to it even though it was owned by your next door neighbor since 1935 and never left the house (no public history). This seems to be primarily because the sound of the instrument is so highly valued that doing anything other than fixing structural problems risks altering that sound if only in subtle ways. Making cosmetic changes or refinishing is nearly always a bad idea from a valuation perspective, unless it is to undo modern cosmetic changes, e.g. changing the pick guard.
Drums seem to be less sensitive to this. You can replace all of the rusted hardware on a shell without altering the sound in any detectable way, so that criteria doesn't really work. The heads are consumable just like guitar strings or tires on a car. Whether you make cosmetic changes to a drum or not seems a personal aesthetic choice if you are planning to play it.
I currently have a 1950 or so Ludwig classic set that has some rust on the hardware but nothing that can't be refinished. The questions are: replate all the hardware? Replate only the badly rusted ones? Remove the rust and leave it in its original condition? Replace the rusted hardware with more modern but matching parts? To me the questions have to be answered by economics and how I want the set to look.
If I intend to play it and care primarily about the sound, then it doesn't really matter which path I take and the cosmetics need only be "good enough for me." If I'm going to sell it, I probably would do nothing to it and leave that up to the buyer. If it is for my collection, then restoration to the greatest extent possible is probably the right choice. On this set, I'm inclined towards eliminating issues like rust but not removing signs of aging or altering the originality any more than needed.
There are no easy answers.
Jim