ghomma, "Is that clearer now ?"

Yes. And I could have been clearer myself. What I meant was not to transfer the old UV map to the new in some way but to save the material selections. It is the selections that is 90% of the work. Once you have the selections saved it is a breeze to make the UV map. So when you retop the selections one by one you keep control and can make the new selections very similar to the old - any faults.

It was not me who did the first map for the tri version, it was the map such as it came from Marvelous Designer. Usually MD's maps is first class (because you START with the patterns, not the normal other way around). But in this case there are problem because the right front of the jacket touch the left and the meshes intertwine. In the quad version this will not be a problem.