bsg1 said:
like with all collectibles, it is most prudent to use the least invasive technique/application possible to clean/maintain a piece. for myself, using a wire wheel is the end of the line.
one of the biggest mistakes many beginning collectors make is trying to make an old tool/collectible look new again. over cleaning is irreversible and will lower the value of a collectible as well as diminish the beauty of a piece that only time can bring.
Private Lugnutz said:
And it almost always alters the original finish or leaves marks.
There is no standard, per se, but the use of a wire wheel, no matter how soft, well-worn, etc, has been a line a lot of collectors will not cross and don't want crossed by others when it comes to exchanges (trades, acquisitions, etc). Me included.
(* emphasis added *)
^ I doubt anyone is going to put it any more clearly than those two statements.
When in doubt,
don't.
It cannot be undone.
I received a package from Ebay a couple years ago. Several miscellaneous sockets and other items. Down in the bottom of the box was a #3208 Indestro Super 1/2" drive speeder that some knucklehead put on a
very coarse wire wheel. Its minimal value (considering they are ubiquitous and there is little, if any, demand for them) has been reduced to less than zero (if that were numerically possible.)
A little paint thinner, scotchbrite pad, and
maybe a bit of #0000 steel wool sometimes, being very careful not to remove the original patina of the item. Anything more than that (except, as noted above, on "users") and you're destroying the "collector value" of the item.
Here's a good example that was posted last night on Ebay:



^ This one is particularly egregious, because what little, if any, of the original "copper oxide plating" that was on the item has been removed. I find stuff like this on Ebay all the time and my first thought is
"IDIOT!"