This is how far I am.
Yes I figured out that the "awardsitems_x" files are the ones that need changing.
I did edit them, simply pasting the italian medals over the corresponding german ones.
But alas! instead of a shiny medal there is only an empty background!
I successfully implemented them for the crew management screen
They are: - u-boat sign = distintivo sommergibili
- u-boat front clasp = distintivo della divisione atlantica
- iron cross 2. class = medaglia al valore di marina in bronzo
- iron cross 1. class = medaglia al valore di marina in argento
- german cross = medaglia al valore di marina in oro
- knights cross = croce di guerra al valor militare