David Adelman is now more than a just fan of the Philadelphia 76ers. He's part-owner.
The Philadelphia businessman — and the face of the team's proposal to build a new $1.3 billion arena in Center City — announced Thursday evening he has joined the NBA franchise's ownership group after acquiring a stake in the team from Fanatics CEO Michael Rubin.
Rubin, a resident of Bryn Mawr, said in June he was selling his 10% stake in Harris Blitzer Sports & Entertainment, the company that owns the Philadelphia…