Two for one: The trend of restoring brownstones to single-family use continues: The buyer of 429 East 85th Street has already started combining its apartments. It was a yearlong path to the sale, as several deals fell through and two Realtors jumped ship. “It wasn’t a problem property,” says Lydia Rosengarten of Leslie J. Garfield & Co., who finally sold it. “The seller just wanted her price.” Alas, she never got it: She asked $2.7 million and sold for $2.275 million.