RTL vehicles had bodies manufactured by Park Royal, Weymann (30 vehicles) or Metro-Cammell.  The Metro-Cammell bodied buses were RTL 551-1000 (450 vehicles). They had 56 seats, 26 lower, 30 upper.  The RTLs were originally allocated to particular garages which were Leyland-only, resulting in most bus routes being either AEC or Leyland.  In later years some garages had a mixture of AEC and Leyland buses.  As passenger numbers fell during the 1960s, London Transport sold off the Leyland buses, preferring to standardise on AEC vehicles, although some of the Routemasters which eventually replaced the RT were Leyland engined.

RTL 326 entered service at Tottenham garage on route 73, subsequently working from Seven Kings and Stockwell.  After disposal by LT she worked for West Herts Coaches and Kirby's Coaches of Hertfordshire.  In 1974 she was acquired by the East London Traction Society and restored by them, but was sold on in 1978.  After several years of open storage at Billingshurst, she was moved in 1999 to the Leyland Museum at Preston, where more restoration work was undertaken.