There should be more proof marks and choke markings further up the barrel.
The proof marks will tell you something about the date it was made.
You should find a number "18.?" which will be the actual bore in millimeters, and then another number less than that, such as "14". That is the choke in millimeters.
I think that the engraving is factory. The motifs are pretty standard for Italian guns.
Apparently there are several grades of Aristocrat. Here is a list describing the features but no photos.