Thank you to all who responded to my plight. Brian & Wolfgang were the
closest to the solution. It was actually quite fortunate that the problem
stopped becoming intermittent right in front of my house. That made it easier
and convenient to isolate the problem.

I had tried banging on the starter with a broomhandle w/o result. All I could
manage was a tap. After reading the various suggestions, I was encouraged to
concentrate on the starter itself. I surmised that I simply needed something
heavier to BANG on it.

I got a tire iron and worked it in the confines above the starter. A few
solid whacks later, and she came unstuck.

Now I know that I HAVE to replace that starter. I don't feel so bad having
already bought one.

BenT
San Francisco