I finally took it apart and looked. I didn't find excessive corrosion on the exhaust pipe, any holes, or anything missing. I did notice that the pipe is held rather firmly by the hanger at the back of the transmission and tends not to be centered in the manifold when the clamping ring is removed. I put the ring back on an tightened it down. I still have the leak. Should I loosen up the hanger at the transmission, get the pipe well aligned to the manifold and tightened down before re-tightening the hanger? Any other ideas?

In other news, I noticed lack of vacuum after I did the exploratory on the exhaust system. I'm thinking it's just a leak in a line somewhere.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.