E. 24th Street at 21st Avenue
Unlike my previous Powell Bros. Concrete Co. mark, this one has (narrowly) escaped damage. Still looking for one with a date.
6130 Medau Place
I’ve documented this mark with dates from 1926 to 1940, but this post is just to document the J. H. Fitzmaurice mark as a type. As far as I know now, it’s the second type used (after the escutcheon version), but the third type (the oval text version) overlaps with it. At least two different marks followed with the barrel configuration, like this one.

3361 Partridge Avenue
I would bet a quarter that these guys are related to B. W. Martinelli, of Castro Valley. This mark is older, I am sure.

4664 Dolores Avenue
Another company from the Bacon Block, joining Harry B. Williams and Golden Gate Construction Co.

1811 E. 21st Street