So I called the PO. He said that he sold the car to me for about what he was into it for. It was not running when he got it, and he removed the clogged-up Racor filter and flushed out the fuel tank. Then it would start, but wouldn't shut off. So he bypassed the vacuum system. (No mysteries here, yet.) The people he got it from had received the car in lieu of money they were owed, so it probably didn't run then. That owner was some girl described as a bit of a 'flake', and there were three-year-old plates on the car at the time. So, lost in the misty past is what could have happened to the car, but it is not out of the realm of possibility that the 'flake' utilized a bozo mechanic who turned a running car into a white elephant. _My_ white elephant!
So, a botched chain installation is still high on my list! -- Jim