All of these stamps were found in the Point Loma neighborhood of San Diego.
Butterfield 40, Unocal driveway, Rosecrans Boulevard south of Shelter Harbor Boulevard
F.K. Hawkins, 8-27, 3230 Garrison Street
Griffith Company 1948, corner of Evergreen and Emerson
Ted L. Vance & Sons Corp., Harbor Boulevard at Harbor Island Boulevard
The Ted L. Vance stamp was actually in the curb, and is far newer than any of the other stamps depicted here; it was on a relatively new sidewalk along Harbor Boulevard, see below.
Luke's Sidewalk Stamps, Other Cities: Bakersfield, California | Oakland, California | San Francisco, California | Santa Barbara, California