2419 26th Avenue
I thought this was 1912 at first, but 11 years later I looked at it again and decided it’s really 1913.
4500 block Bond Street
In a comment elsewhere on this site, Harold W. Smith’s daughter said, “My father did a lot of concrete work in Alameda and Contra Costa County. He came to California from Kansas, riding the rails as a young teenage during the Great Depression. He got his cement contracting license in the mid to late 1930s. He’d used the stamps mostly in his earlier work.” He lived somewhere other than Oakland.
Smith used the exact same escutcheon as W. H. Fitzmaurice‘s first mark, which it used from 1922 to 1925. I think this is the only example I’ve seen; in any case, I found no example with a date on it.