Yup, George, looks like that's where the problem hangs out. I plugged the hose to the auxiliary air valve and the revs dropped to about 900 rpm. After the engine got up to temperature, I reconnected the hose to the a.a.v. and the surging started again. Guess I'll have to go hunting for another a.a.v. It's annoying, though, that the thing should have gone on the blink sitting in a plastic bag while I did the engine work. It gave me no grief before.

John, the vacuum retard hose is disconnected and its nipple on the manifold is plugged. I was already running the thing that way before.

Michael, there is an issue with the timing. It's running way advanced, but I haven't been able to retard further because the vacuum regulator sits jammed up against the block. Something definitely wrong there, but I figured I'd deal with one problem at a time. A multi front attack may, however, be needed.
Thanks all,
Bob S.