I decided to cut away the middle section between torpedo doors.
Than marking the silouette of the PE part on the model i cut the needles plastic away leaving 2-3 mm edge as support.
...most feared part of the build is actualy not that bad at all. The PE takes a lot of shaping , but with plenty of time and patience the results are good.
...now it should sit in the groove neatly.
TBC...