Well,sometimes there is someone living near Vicenza,where there is one of the biggest US Army base oputside US now home of the 173rd AB,that sell some militaria.Mostly is modern militaria,sometimes but not so often something older shows up by these sellers.Anyway they have no shop,they mainly sell at militaria shows.
There are also some dealers (they sell on internet too)that sell a lot of modern era american militaria,mostly for sof air fans.
Mainly we have to get the VN-WW2 and WW1 era items from american dealers....
When it comes on 2nd ww militaria something still shows up at fleamarkets around Italy,but in this case too not so often.
I guess it must be the same

for american collectors looking for italian militaria in the States...
I have one internet address of a dealer who has a quite good catalog,anyway remember we are always talking about someone who get its stuff from the USA.