2630 California Street, Berkeley
The third date I’ve found for this particular maker, “Burnham Co.” as opposed to “C. B. Burnham.”

2755 E. 7th Street
It caught my eye and wouldn’t let go. It’s the only Azorean Construction Co. stamp I’ve found with a date.
1321 96th Avenue
I believe this is E. Nelson, who was responsible for various marks, with and without Johnson, in the early 1910s.