We checked the Polk City Directory. The first year that S. Choctaw was listed as a street separate from Choctaw Dr was 1959. Not sure if this means it was paved, but it was a recognized street if it was listed.
If you need further information, please call the Baton Rouge Room Archive at 225-231-3752. Our archivist may have maps or government documents from that period that can more surely answer your question.