Like Valarie, no luck on Pietro. But I'm not sure if you have this manifest for a G. Briscione (#370), age 30 yob about 1857--possibly Gabriele?; and a B. Briscione (#372), age 25 yob about 1862.
Olympia arrival New York 12 April 1887.
http://img381.imageshack.us/img381/4527 ... 887fe4.jpg