2900 Viola Street
Here’s another specimen from W. Pool. I wonder if he lived nearby.

1368 Holman Road
Herman C. Orth was a cement contractor who lived in Berkeley with his wife Helen at 1821 Addison Street, according to the city directory of 1925. He was also part of the Orth & Braun firm. I have examples of this mark all the way to 1951.