I think you may find it easier to find the brand of gears that are made in Italy, and then try and deal direct.
Shipping on a set of gears like these would be very very expensive
I got the 4.6 diffs out of a 2.8 diesel swb GQ.
Changed from 4.1 to 4.6 , I run 35" on the road and 36" Simex for playing, also a lot better for whinching.