Midland Red's final series of buses to be built at its Carlyle Road Works in Edgbaston, Birmingham were single-deckers comprising semi-coach, dual purpose and service bus variants - the S21, S22, S23 types respectively. They were mechanically similar to the earlier S17 models but the bodies were updated with longer windows and peaked front and rear roof domes.

The S21 semi-coaches were intended for lighter bus services during the week and coach duties at the weekends. The better appointed specification included forced ventilation through roof scoops, more comfortable seats, luggage boot, and coach livery graced by polished grille and mouldings.

Their work as relief coaches meant that the 30 S21s were spread widely around the system, one or two featuring at many garages. 5868 entered service in July 1967 at Malvern garage, remaining there until the small garage closed in October 1976. It then worked from Bromsgrove until transfer in March 1979 to Wellington, becoming a 'float' vehicle finishing at Swadlincote in February 1980. It then passed to the Museum and soon repainted. It fortunately retains its original style seats and luggage boot.