We've had a few posts about Tanner Motor Livery recently, but I haven't seen any mention of this phone number before. The OXford exchange would suggest Pico Rivera/Whittier, but they seem to be advertising their branch at the Beverly-Wilshire Hotel. Any guesses? Their number in San Diego was Main 3111.
www.cookbkjj.com
As well as Tanner Motor Livery limousines, there was also Tanner Motor Tours operating The Gray Line. These brochures all date from the '30s and '40s (according to their sellers).
All from Ebay
These tickets/passes are even earlier. Note the TRinity phone number and 324 So. Beaudry address on the one from 1927.
Ebay
Tanner Motor Tours could even meet your ship for a day-long tour of the city. This poster is dated 1928.
USC Digital Library
The picture below shows one of Tanner Motor Tours' Fageol Safety Coaches in 1931.
USC Digital Library