The location could also be a clue; Fosco stated that the location that it was somewhere to the northwest of Chicago (can't remember his exact statement) and Amato and Potenza - two guys who operated out of that area for the Outfit - are apparently present. Maybe some of the guys are operatives out of that area who don't have existing photos.
"As I said, I am not sure of the location. However, based on input by a living relative of one of the people in the photo, it is likely that the get together took place at Holiday Park (which was/is a beach), near Wauconda, Illinois."
