Site would be under the county -- Bexar.
1930 census739 Hollywood St., 4th ward San Antonio, Bexar Co, TX:
Cuthbertson, Robert M., h, 41, Md @ 39, b TX, TX, TX
" Pauline, w, 27, Md @ 25, b TX, AL, AL
[Robert is listed as traveling salesman, wholesale paint ___ can't read last word]
I would contact the public library in San Antonio, see if they have any old city directories for the time period you want.If they do not, ask if they know a library that might have them.One of the larger genealogy collections may have city directories for other TX towns, such as Dallas Public Library, or Clayton genealogy library in Houston.
This looks like the same Robert, mother's surname is different, may have remarried.
1920 census 204 McGowan, 4 ward Houston, Harris Co, TX:
Lee, Debbie, h, 48, md, b TX, MS, TX
Cuthbertson, Robert, s, 31, sgl, b TX, PA, TX, painter, paint co.
" John, s, 29 sgl, b TX, PA, TX, salesman shoe co.
Robertson, William, roomer, 31, s, b TN, US, US clerk, electric
Currie, Vick, roomer, 35, s, Brazil/Am Citz, MS, TX, salesman, oil co.
Happy Hunting (^_^)