The adjacent Wolferman's Building was under construction in 1923.
Photo from State Historical Society of Missouri / J.C. Nichols Company Scrapbook

Wolferman's opened its On The Plaza store in January 1924. It included an on-site bakery, where the famed Wolferman's English Muffins were made. The original Wolferman's was not a self-service operation, as was Piggly Wiggly. Wolferman's customers were served by store employees who assembled their orders.

An interior view of Wolferman's On The Plaza. Although the photo source lists it as being taken in the 1920s, the women's fashions indicate that a 1940s date might be more accurate.
Photo from State Historical Society of Missouri / J.C. Nichols Company Scrapbook

The Tower Building joined the PLAZA in October 1924. One of its charter tenants was The Avon dress shop.
Photo from State Historical Society of Missouri / J.C. Nichols Company Scrapbook