Cathay House, hailed by The Chronicle when it opened in 1939 as the “fanciest” restaurant in Chinatown, quietly closed this spring. Now the Yeo family, which owns Straits Restaurant and Sino in San Jose, is taking over three of the building’s four floors and reopening as two separate restaurants, Cathay House and 601 Dupont. Within a month of the original Cathay House’s opening, Dr.