The verdict. We had no less than 2 cracked pipes directly underneath the upstairs bath, and one of them was not a 'sewage' pipe and would have had to have been replaced at some point anyway! So, we now have 2 new pipes, a new bathtub faucet and knobs (since they were leaking into the wall)....and a giant 3 foot by 1 foot hole in the ceiling of our living room!
Plumber repair completed - check!
Sheetrock repair / Painting - to be determined!