Clarified Ruggiero Boscovic's father's side issue - Orthodox Slav as best acceptable solution for this problem since in the 18C Croat and Serb were not widely accepted classifications.
Britannica link is inaccurate as it cites Zdravko Marulic's work on Boscovic which used present day ethnicity and country of birth...
Boscovic ought to be called what he was a Slav-Italian scientist who most likely called himself Dubrovcanin...