thanks for the information. Due to the high cost to have them shipped to Italy, I will probably try to fabricate the connectors and the braces by myself too.
Yesterday I looked carefully to the trunk pan and I think that it was porobbaly replaced with a non correct piece. Taking a look to another post (Sean), I have undertood that 1970 trunk pan has the hole on the top of the humps. The 1971-74 does not have the holes on top of the humps rather, they are on the rear facing sides of the humps.
AMD is the only one to have the correct part, while Goodmark has a common replacement for all the years (70-74).
My pan seems to have no holes at all: