This 1930s photograph may very well show the same Owa as mentioned by the author. Interestingly, the Owa is visiting the Methodist Mission Society Hospital that the author actually worked in.
"The Owa makes his annual visit" The Owa, chiefs and retainers on the verandah of Ilesha hospital. The Owa had provided the land for the hospital and showed considerable interest in the work carried out there; From a set of lantern slides entitled "Ilesha" introducing and describing Wesleyan Methodist work at the hospital and medical mission at Ilesha, a Yoruba town, the former capital of a kingdom ruled over by an Owa. Medical work began in 1916 with the opening of a dispensary. The construction of a hospital followed in the 1920s. The hospital was expanded in 1934.
Image courtesy of SOAS
Letter From West Africa Article