Chopps, I agree. There is not much out there on Riviello. I have seen his name being spelled "Raviello" also. If you try this name when doing the research, you might find some more on the dude.

Bill Bonanno described him as a knucklehead soldier who operated numbers lottery for the Family in East Harlem.

During the Bananas War, a Bonanno supporter by the name of William Gonzales (associated with Vito DeFilippo) was shot while riding in a car in the Bronx. He survived. But later investigation showed that there had been three others riding with him in the car; Vito DeFilippo, Patty DeFilippo and Willie Riviello. These three (who must have been the prime targets in the attack) escaped unharmed.

And in Herald Statesman (May 30, 1984), I found this article:

"Man sentenced in extortion conspiracy"

"A Bronx man was sentenced to four to eight years in prison by a Rockland County judge Tuesday for masterminding the attempted takeover of a Blauvelt restaurant.
William Riviello was convicted in March of conspiracy and extortion during a trial in which Organized crime task force investigators testified that he tried to forcibly take over Vincent's Restaurant, which is now closed, on Route 303.
Riviello was accused of directing two Rockland men to beat the restaurant manager, Daniel Addesso, who suffered facial injuries that required more than 140 stitches and surgery. The men, both armed, went to the restaurant on March 6, 1982, beat Addesso, refused to pay their bills and raised and lowered the lights and music at will, according to testimony by the restaurant owner, Vincent Cipolla.
On Tuesday. Riviello's lawyer. Murray Richman, asked Judge Robert Meehan to impose the minimum sentence in view of his client's record, which he said showed "no background of violence." But Assistant State Attorney General Michael Goldsmith said Riviello's "extensive criminal record (should) be given serious consideration."
He said Riviello's actions were "typical of sophisticated organized crime. This was part of an overall pattern of criminal activity."
Goldsmith said Riviello had a prior gambling conviction in the Bronx and was linked with gambling activities in Pomona, Manhattan and Westchester County."

///In the 1980´s FBI listed his home address at 1133 Lydig Avenue, Bronx