Binnu is sicilian for benny, as Lee already said it.
Zu means Uncle.
Why binnu hid before u curtu? i don´t know i think they were searched for diffrent crimes.
In the sixties the Corleonesi were already mighty, but not the most powerful. for a long time Leggio reigned in a triumvirat with bontate and don tano badalamenti. But they were already gaining power: most important were 3 things: get there ally Santapaola in power in Cantania by killing old boss Calderone. and the same for the Madonias in provinicia di Caltanisetta by killing the Tiger Di Chritina. And they were able to exclude Don Tano from the CN, for some wrongdoing. Of cours this was all very secret, the Palermo bosses around Bontate and Inzerillo had no proof for it. And they also cared to less, they were to busy making big money from drugs and construction (2. sacco di Palermo).