This rather lovely ghostsign advertisement for Trendell's can be found on the side of a red brick building on the corner of Thurlow Gardens, Wembley.
It looks 1930s to me. As you can see, they would have been an up-market company offering [chauffeur-driven] Daimler vehicles for hire.
Note also the pre-1966 phone code WEM-1567, where WEM is short for Wembley and would have been equivalent to 936 on a keypad. More old London phone codes here.