SW:

1) The term "4Gtronic" is not really used in the field. It is a marketing dept. term.
2) Your original transmission is a 722.3xx.
3) You could go down the road of backdating to the 722.1xx; it would be very helpful to have the donor car side by side with the recipient. There are a number of small parts that are unique to each package (and some large ones).
4) The straight forward resolution is to find another 722.3xx as a core for rebuilding.
5) The switch to a M/T is the most complex solution.