6745 Harrisburg Blvd. – Houston TX (built 1926, multiple additions)
This Southwestern Bell Building in southeast Houston has had several additions over the years, including a third floor and a rear expansion doubling its footprint. Architectural details of the original building still remain over several windows and doors.
The following image is from this advertisement for Southwestern Bell Telephone Company in the March 2, 1950 issue of the Southwestern Citizen: