Father of his Family for 20 years, yet the most we know about him is from Bonnano's book. and its not a lot of info.

we found out more about Gagliano in recent years, wondering if we will know more about Mangano.

and also, was he exclusively the boss, or was his brother equal in power? did they rule together?

Most of the books I've ever read on it (Mafia Dynasty, Five Families, The Most Evil Mobsters in History,) list Vincent as the formal boss. Like the man it's based on, the book "The Last Testament of Lucky Luciano" is full of different "facts" on the subject. In one spot the book speaks of Vincent as the boss but in another place it talks of the Brooklyn outfit run by the Mangano brothers.

For what it's worth a 1963 Senate organized crime chart does show the deceased Anastasia as successor to both the Mangano brothers.

My take is that Vincent was the boss and when he wasn't around Phillip spoke for him, even though Albert was the underboss and had more power than his supposed bosses.