Well, it sounds like a beautiful gold chain in any case. Could it possibly really BE an Italian gold chain?
Concerning the female end of the clasp that you mention with a lozenge with a (star 1 AD or perhaps AP) - I assume the star means it was made after 1968, in Italy, the number could be the assigned number of the registered jeweler in Italy and if the letter marks are AP, this would stand for the Italian Province Abbreviation - for the Italian province - Ascoli Piceno.
Renee
Rating
UnoAErre Italia Gold Chain by: Joyce
Guil - "UnoAErre Italia, which is based in Arezzo, is an Italian goldsmith and jewelry company. UnoAErre is one of the world's largest company specializing in the manufacture, distribution and export of gold and jewelry worldwide.
These days in its production, the company uses equipment designed to complement the traditional craftsmanship of the Arezzo goldsmiths with the latest modern technology."
Your piece is most likely done by an Asian company 750 means 18 karat.