See the following link for some discussion about the 1930s Andrew Williams shopping center and the M/B Center that replaced it in the mid-1960s: viewtopic.php?f=27&t=1257&p=7679
I recall seeing a photo (not high quality) of the Andrew Williams shopping center in the Oakland Tribune
Yearbook for 1939, 1940, 1941 or 1942. As you know, it was located at the intersection of U.S. 50 (today's I-580) and State Route 24. U.S. 50 (MacArthur Boulevard, then known as "Moss" street) was a major access road to the Bay Bridge that had just opened in 1936. State Route 24 was and is the main highway connecting Walnut Creek and central Contra Costa County to Oakland; the Caldecott Tunnel (then known as the Broadway Low Tunnel) had just opened in 1937. The shopping center (one of the first supermarkets in the U.S. to have a parking lot) likely was located there in the late 1930s to take advantage of the new traffic patterns related to the openings of the Bay Bridge and Caldecott Tunnel.
If you have any memories of the Oakland Andrew Williams store, please post them on this board. Many readers would be interested to learn details about shopping at this pioneering supermarket.