One of the founders of Kelsey Seybold lived in a fancy River Oaks estate at 2136 Brentwood Drive.
It's now a City of Houston protected landmark.
https://www.houstontx.gov/planning/HistoricPres/landmarks/07L174_Dr_Mavis_P_Kelsey_Sr_House_2136_Brentwood.pdf
The Dr. Mavis P. Kelsey , Sr., House at 2136 Brentwood Drive was built in 1940. It is an impressive example of the Greek Revival style home, built as a speculative house by C. C. Rouse in River Oaks. It was first occupied by the Wollmer family. The home was later owned and inhabited by Dr. Mavis P. Kelsey, Sr., for many years. Dr. Kelsey is most notable as the founder of Kelsey-Seybold Clinic.
The original cost summary prepared by C. C. Rouse and dated October 9, 1940 estimated the cost of building at $11,486. Records show that the actual cost was $12,241. The home’s first owners, the Wollmar family, purchased the home for $24,500. The sale was made by George P. Wright of the River Oaks Corporation.
https://spencerhoward.net/portfolio_item/brentwood-residence