If the evaporator repair is considered the top $$$ repair on the W124 hit parade, then I just got past the #2 repair, the headgasket @127k.
While talking with my indie, he suggested that my engine was now good for another 100k (knock on wood).
We touched on what else could happen in this mileage range and he said the the tranny generally lasts between 150k-200k but not to fret because this was a routine repair, parts readily available and this guy up the street does them all the time for around $1500. (the head gasket cost me $1675).
So my impression was that a rebuilt tranny was down the list on the W124 worry list.