For the record I'd consider Rocky Kansas, Young Corbett III Johnny Dundee Americans and Kalambay as Italian.
Yes people get nationality and ethnicity mixed up all the time, and as you suggest, I suspect that is often done deliberately for one reason or another...
Fitzsimmons is a Kiwi, an Aussie or a Yank. Bar some papers calling him a 'Cornishman' I don't think he was in spirit, at all.
If people are considering italian-americans as italians......well, Locche should be considered italian too ?? Not really IMO...
Marcel Cerdan was born in Algeria and raised in Morocco. He was talented, but I've always believed he was more of a star than a truely great boxer. That's just my opinion.