Lincoln Avenue at Broadway, Alameda
I took another walk in Alameda and found another year! This is Rosas Brothers’ older stamp, which they have kept updating.
400 block Marshall Way, Alameda
I took a hike through Alameda and spotted dozens of tempting sidewalk stamps, many of which I have not seen in Oakland. I ignored those. But some, like examples I’ve posted from Berkeley, add new dates to the record of Oakland sidewalk makers, so here’s one that adds to the single dated example I documented in Oakland.
28th Street behind the Humanist Hall
Now this is interesting. In 1940 Chas Somers and Sons changed their stamp. From the 1930s to early 1940, the stamp included the firm’s phone number “NIGATE- 7470” at the bottom: see it in 1938, 1939 and January 1940. And here, as of March 1940 (I think), is the earliest instance of the stamp they used for the rest of the documented record, with the notation “PI. 4041J” at the bottom, as seen here beautifully in 1946.

702 Solano Avenue, Albany
I have only a single Lee J. Immel mark from Oakland, which I think is older than this one.