Loyalty Building, 1928
The Loyalty Building sign completes a set of four similar signs, each displaying its own building name, all in the same area, and all the buildings are of roughly the same era. Also, all four signs are being currently maintained, so are not officially "ghost signs."
The Loyalty Building is at SW 3rd and Alder. The sign can be seen from the street at 5th and Alder, or, as I've done here, the top floors of the the parking garage south across Alder.