The Old-House Journal has published a catalog of products available for restoring and decorating old houses. More than 1,100 items are listed in the book, which is available for $10.95 from the Journal, 69A Seventh Ave., Brooklyn, N.Y. 11217.

Sandoz Inc., a brokerage firm with an office at 5100 Wisconsin Ave. NW, has opened a division for the sale of cooperative and condominium apartments. Nancy Harris Goldstein has been named vice president and manager of the division.

Owner-Seller Service Inc., a firm based in Bethesda, has extended its flat-fee residential brokerage service to home sellers in Virginia. The firm's $895 flat-fee service now is available through John Hitchcock's Town & City Homes Inc. in Reston.

Making housing a national priority will be the subject of a governmental affairs conference to be held Feb. 22-25 at the Hyatt Regency here by the National Savings & Loan League.

The Prince George's County Board of Realtors has launched a residential renovation competition with $2,650 in cash prizes available to county home-owners who renovate or remodel the exterior of their dwellings. Entry forms are available form the board office in Largo or by calling 350-7700.