If the T&P was leaking at 104 PSI then it was bad because it shouldnt open up until the PSI reaches 150. You need to replace it.
The upper stat tripped most likely due to an element that shorted even though it ohm tested O.K., the bottom element does most of the work.
A PRV and expansion tank should have been suggested with a 105 PSI reading
They will be calling you back soon.
Unless you were doing all this as a favor you don't seem to have enough knowledge to be working on and billing people for this work.