It’s one of those ways in which one has to know the ebay jargon. Vintage seems to mean a recent example of something that’s been around for awhile. If it really is old they’ll call it antique.
Don’t bite Dale. Nanohedron is only partly right. I may not currently have a such a vintage Sweetone, but for eight bucks I’ll be glad to vintage one of the mundane ones that I do have. Heck, for only nine bucks, I’ll vintage the blue Sweetone C that got sat on and has a sort of wrinkle partway down the tube. Then you’d have a vintage instrument with character
It isn’t just eBay. The geniuses in marketing at Fender Musical Instruments came up with a clever idea a few years ago. Basically, what they do is take a “re-issue” guitar (re-issue guitars are another silly idea, but that’s another story) then they have the “custom shop” turn it into a “relic.” They let some of the metal parts corrode, beat, gouge, and fade the body, apply cigarette burns to the headstock, etc. Then they sell this “Fender Relic” for $2500 instead of the $900 the basic reissue guitar would sell for (and even that’s an inflated price, IMHO).
A practice during the “antiquing” craze in the U.S. (not only do I remember it, I even aided and abetted my mom on a project or two…good thing I was a minor and exempt from prosecution) was to take a length of chain and do the obvious thing with it.