I also think the shop should warrant a seal for more than 1200 miles and I will find out tomorrow...
As I understand it, most of the work is in the removal of the transmission, thats why I thought of a rebuild.
As far as I can tell, the trans. works fine and the passengerside does not leak. Only that little siverdollar next to the modulator(?) and the pan, which is what I wanted to address now. And while having the pan off, replace the B2 piston.
But maybe it is best to keep these items separate and have them just fix the seal. Can I trust that mechanic with more work is really the question.
As an aside, some people recommended to leave the seals alone. Just my kind of luck.