Why Italy ?
.800 standard was used in many countries.
And more likely 20th century because old standards were replaced with millesimal standard in late 19th century (again, in several European countries).
For Italian marks see here:http://www.silvercollection.it/italianhallmarks.html
I doubt the maker can be identified unless more marks with this pattern emerge.In a word, initials and 800 is just not enough for any search, waste of time.