Problems resolved:
1) 3rd brake lite had broken +12V wire in the harness, exactly where the rubber strain relief sleeve ends and enters the guide along the trunk hinge. Poor design IMHO, bending wired nearly double with every opening and shutting of trunk, but it looks nice before it breaks. I expect they ALL will break there sooner or later, ya'll should put it in the FAQs

2) Advance Auto parts sells and an exact replacement battery. Rated higher amps then the OEM Varta/Mercedes batt., same dimensions as original, with same plastic (+) term. cover.
Called their "International Titanium" battery, group 49-1 and cost $70.

3) Bobterry's advise was spot on(thanks Bob) , Rollbar and top indicator lites being on had to be re-set with MB computer at independent MB shop (MBV Auto in Charlotte, good folks BTW). In chatting with mechanic, this is SOP any time a battery is discharged completely or disconnected, their charge to re-set lights/computer is $80.

Add the two charges and that about equals the price of a MB dealer battery less install labor and resetting computer.
MBV tech's advise on removing/installing batteries is same as all other manufacturers, remove ground cable FIRST to disconnect, install ground cable LAST to connect, don't jiggle it on/off/on/off.

Next time I cross this bridge there will be an aux 12v batt firmly connected in parallel to vehicle batt to retain all computer memory before pulling the dead batt.
Lucas electrics on my TR-4 are much easier to deal with!

Mike Kelly
Stanley, NC
K1200RS