Msycamore, huge breakthrough about the story of the Italian release.
In a book fair I found a guy selling all sorts of cinema posters (the father of this man owned a cinema back in the days). I asked if he had THX and he said unfortunately he didn't bring it but he does. He told me he had two sets, one from the first release and another from the second release of the movie that came years later. So the film was indeed released in Italy in two occasions (first release and then Lucas re-release 8 years later), this is confirmed.
I told him about our project and he was happy to know that we used Averardo Ciriello artwork for the DVD cover. He told me the very first release had that cover while the second release came with photographic posters (not artwork).
2004 version has not been released in theaters in Italy.
The guy lives in Ravenna he told me I could go visit him. Italian posters from the 70's guys, if anyone wants them he sells them for 10 euro each (way cheaper than ebay) and he's got plenty of them (the full set that they expose in the theatre hall and outside). I think I'll buy myself the Averardo Ciriello one. I would need to drive up to Ravenna which is not too far but neither behind the corner. However I'm curious to go there and photograph the stuff he has, probably there are posterst we don't know about.
Well this is my news, if you fancy updating what we know about the history of Italian release