I often have that very debate with myself. Today, I'm carrying a circa 1925 Sperry & Alexander easy-open jack that's simply beautiful. It's been cleaned and sharpened, and I don't think the nickel silver bolsters made it through the last 75 years unscratched, so it's been buffed. The blades, however are probably exactly the same shape as they were when it was made, and the jigging on the bone handles has its own subtle beauty. It's in my pocket by mistake, because I grabbed it instead of the 1950's Schrade Walden jack I usually carry. I am terrified of losing any of the older knives I tend to carry with me, and of having them rust or get dinged up, but that just makes me more careful with them. I nearly bought one of the Marble's easy-open jack knives to carry instead of the S&A simply because it could be replaced, but the new production Marbles would have cost more. The way I look at it, if the knife has been cleaned up in the past, like most of mine have, they can be cleaned up again in the future, and no one will be able to tell the difference. If you subscribe to Bernard Levine's view that a refinished antique knife is worth much less than an untouched one, then by all means leave it at home. Case knives are another possible exception as well. I seem to remember reading that Case collectors tend to be more finicky about condition than other specialty collectors, and even polishing can reduce the value of previously mint Case knives. I always have another knife on me for messy work, though, such as a Benchmade 705 that helps keep fruit juice and packing tape off the blades of my vintage knives. If you're really concerned, get a leather slip sheath for them, resign yourself to losing a bit of their resale value, and keep them in a pocket that buttons. Make them special, but carry them. After all, someone else will eventually own them anyway...
