Business Incubator Center: The Phi Beta Sigma fraternity and the Black Employees Assn. will open a new small-business incubator center Monday on West Vernon Avenue in the Leimert Park neighborhood of Los Angeles. The center will be located in a surplus building the organization acquired for $1 from the U.S. Postal Service and moved from Downtown with a financing package from private citizens and local financial institutions. The building will house eight small businesses, to be named Monday, that will share certain administrative services. It will also be the home of the recently organized South Central Peoples Federal Credit Union and the administrative offices of the Black Employees Assn.