Although concentrating resources on its core service network was a Central SMT hallmark, it nevertheless maintained a small, dedicated coach fleet for private hire and excursion work. Throughout the 1960s and early 1970s, this small, secondary fleet wore an attractive livery comprising two shades of blue. The main fleet of Duple-bodied Bedfords made up the C series, while a short-lived fleet of Alexander Y-type bodied Albion Vikings made up the AC series. The Y-type bodies on the Vikings were notable for being the only panoramic Y-types bought new by Central and for having no destination box on the front dome.
The C series was reborn in 1984 for - unusually - a mixture of Leyland Tiger, Volvo B10M and Dennis Dorchester coaches. C1 to C6 in this C fleet wore the red and cream livery of the main fleet, but C2 is notable in being one of a few buses to don green EK Chieftain colours when Central tried out local identities in its dying days. C7 to C19 were all dedicated to Scottish Citylink work, Central being a very late convert to express work, and were presented accordingly.