Two gamblers have been released from Montgomery County Prison on house arrest with electronic monitoring to serve the rest of their sentences for probation violations. They had been locked up since late march, when a construction crew dug up nearly $1 million buried in the backyard of one man’s home in the Meadowbrook section of Abington Township. The county initially charged 60-year-old Joseph Mastronardo of Stocton Road in Abington and his 54-year-old brother and business partner John, of Blue Bell, with bookmaking and other offenses. Their business was taking bets on professional and college football and other sports. The dig was apparently part of a wide-ranging investigation into bookmaking, money laundering and offshore and internet betting, and the buried money may have been part of the proceeds, as well as ready cash to pay off winning bettors. The county has dropped state charges and turned its evidence over to federal prosecutors, who are still developing their case. Joseph Mastronardo’s wife of more than 30 years is Joanna, daughter of the late Philadelphia Mayor Frank Rizzo.