Quenton J. (Gabe) Gabrielli, 70, who worked for the U.S. Postal Service for more than 40 years, died of cancer Wednesday at Georgetown University Hospital.

He began working for the old Post Office Department in the late 1930s as a clerk and mail handler. For the last 20 years he had been an illustrator.

Mr. Gabrielli was a noted baseball player in his younger days, both in the Washington area and in his native New York state. He was a catcher on semi-pro teams for about 20 years. He was a member of the WPA team, a government league champion in the late 1930s.

After his playing days were over, he acted as an umpire in Washington-area high school, college and semi-pro games in government and industrial leagues.

Mr. Gabrielli came to Washington from his native Brooklyn in the early 1960s and worked for the WPA before joining the Post Office.

During World War II he served with the Navy's Construction Battalion (Seabees) in the Pacific.

He was a resident of Washington.

Survivors include his wife, the former Dorothy Mae Robinson of Washington; two sons, Peter, of Arlington, and Phillip, of Cambridge, Mass.; a daughter, Adele, of Arlington; two brothers, Jack, of Long Island, N.Y., and Frank, of Arlington, and a sister, Vera Schudelari of Long Island.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.