Hi Jodie, I realize your message is old and you probably have some answers to your questions by now, but in case not here goes:
Many men from Bari who came to this country sold ice and coal including my grandfather, who was from Toritto.
Devito is a very common surname in Toritto, so your friend's Mary DeVito is very possibly from Toritto.There is a DeVito connection in my own family.
My ggg grandmother was Rosa Panza who was married to Matteo Casamassima - both were from Toritto. She would be older than the Rosa Panza who is related to your friend.Based on Italian naming patterns, I'm wondering if your friend's Lazzaro Panza was my ggg granmother's brother or a cousin.The only way we have of knowing is if your friend knows some Panza family history and would be able to verify that there was a Rosa Panza in her family who married a Casamassima.I can't make the connection because that is all we know about our Rosa Panza...that she married Matteo Casamassima.