Updated through on-line information from James R. Stettner. -- The organ was actually originally built for the Marion Theatre in Marion, Ohio and was then installed in radio station WAPI in BIrmingham. In 1953, WAPI moved their studios and purchased a Hammond. An executive of WAPI was a member of Southside, and arrangements were made to donate the organ to the church for placement in an auditorium.
Identified through information from Jeff Scofield: The organ was originally installed at radio station WAPI, after which it was moved to an upstairs auditorium of the church. The organ is rarely used, mostly around Christmas, I understand. Chinese and Korean congregations use the auditorium primarily.