Another Western Horseman magazine ad, from November 1950, shows us a selection of horse figurines -- or at least HSOs (Horse-Shaped Objects) -- available from Dorothy Kindell Ceramics, a Southern California pottery that operated in the 1940s and 1950s.
Some of the names reflect popular horse breeds and colors; for example, "Kentucky Colonel" must have represented an American Saddlebred. And "Flicka" was inspired by literature; the 1941 novel My Friend Flicka by Mary O'Hara had been made into a film in 1943 (and would inspire a TV series in 1956).
I found a photo from an eBay auction of a figurine that appears to be by Dorothy Kindell.
And the Model Horse Gallery website shows some other examples of her work.