I was given this photo of Si & Ezra by my Grandmother, Thelma Stone - the sister of noted CBS author and announcer Fielden Farrington. Grandma thought that Si & Ezra were inspired by Lum & Abner, but since this dates back to 1925, it may be the other way around.
This photo was given to Fielden while he was starting his radio career at WBOW in Terre Haute, Indiana in the early 1930s.
In the above link, it is apparent that this WBOW photo of was used in a postcard.
-Brad Stone