The final customer for the single-deck Dominator were a fleet who had Fleetlines, but only double-deckers, this was Swindon based Thamesdown Transport. A proportion of the fleet had to be single-deck because of railway bridges (like Darlington, Swindon was a town built on railways) and prior to 1980 the single deckers were five Weymann-bodied AEC Reliances, three Leyland Leopard PSU4 with Pennine Coachcraft bodies and five late-model coach-seated Eastern Coach Works Bodied Bristol RESL6G. Thamesdown's numbers 1-4 (FAM1-4W) were the only short-wheelbase single-deck Dominators, type SD132B, they had 40 coach seats in 10-metre single-door Marshall Camair 80 bodies. Unlike the other customers, Thamesdown later took substantial numbers of double-deck Dominators.