Away from politics, Eliot Spitzer has been keeping busy with his family’s real estate business. Last week, the former governor sold a parking garage on East 38th Street underneath the Corinthian, a 55-story apartment building in Murray Hill built by his father, Bernard Spitzer. Spitzer got $10.3 million for the spot, and was praised by buyer Gregg Reuben of Alliance Parking for being “a total gentleman” during the transaction. Both sides were represented by Robert Knakal, chairman of Massey Knakal Realty Services. Spitzer’s big sale comes on the heels of his Washington, D.C., office building purchase for $180 million this summer.