3700 Kansas Street
The first Douglas & Wolfe mark I ever found was a 1931, but it was really decrepit. Not this baby.
3826 San Juan Street
This is probably W. Pool, but for some reason he left off his initial. During this year he also made entirely different marks under the name W. B. Pool & Son.
2721 Sunset Avenue
I think this was done with a stencil and straight cement, painted on top of the fresh concrete. I will guess that the son of W. B. Pool was G. Pool.