Oldest bass was a '56 or '59 Fender P, which was brought to practice one day by the original owner's son (he was the guitarist). I played it for a few minutes. It was pretty nice. He had EVERYTHING, including the receipt, that originally came with the bass. It was fairly worn, but it sounded and felt nice.
I have a '73 Ric and, I believe, a 1970 Univox 'Lectra. I am not sure of the age of the 'Lectra. Though I am pretty sure it is authentically pretty damn old, as I bought it in 1988 and it was old then. The Ric I am quite sure of . . . its serial number starts with MA, it has the checked binding and originally came with closed-back Grovers made of pewter (which were falling apart when I got it, and I changed them to Schallers in 1991 or so).
Old isn't everything, though. I visited a vintage guitar shop in Madison, IN a few months back. They definitely had a ton of vintage guitars, but they were all in horrible shape, and looking around the store I had this feeling I was in the middle of a bunch of driftwood that had landed on a beach somewhere. All of the guitars had that falling-apart look to their finish. It was just kind of weird -- I got the feeling that the guitars were not so much vintage as flotsam. Stuff that nobody really wanted -- though the prices were outrageous.