To close out this thread, here's what I did about the exhaust:
I chose to go with an MB exhaust from the Classic Center. The Center sent the entire exhaust package directly to my mechanic.
Early on a Saturday a.m., the old system pipes were cut in two and removed; the new system was fitted, tack welded, removed, MIG welded, then reinstalled.
Having an exhaust muffler without a 3 inch hole makes a difference. The car no longer sounds like a Harley; doesn't set off car alarms when driving down narrow streets. Even the highway "buzz" at 3,500 revs is easier on the ears.
The exhaust sound is not like my grandma's sedan but has a medium "power" sound, if that's possible to imagine.
So far, seems to be a real improvement.
One of the parts MB sent was a new rubber bumper to fit under the rear of the body just above the pipes where they exit the car. A small flat piece is welded across the two pipes to fit directly under the bumper.The bumper is to prevent the pipes from hitting the body when the road is uneven. If you don't have this bumper, you may be hearing clunks in the rear when the car goes over bumps.
The shape of the bumper has changed. The photo shows the dome shaped older bumper and the flat top current replacement.
Thanks to all for your help,
Richard M, NYC