This kit represents the original form of these eight vehicles. They ran in tandem with a Tavern Car to D2663 (Comet S11AK). However these coaches proved very unpopular, particularly those which operated on the Eastern Region. The high windows made it impossible to see out when seated and the layout, although making meal service easier for the stewards, gave little privacy for the 3rd class and none at all for the 1st class clientele. Travellers on The Master Cutler service were so vociferous that complaints were reported in the Yorkshire local press. All were returned to Southern Region and quickly rebuilt in a more conventional form between September 1950 and June 1951, and given the new diagram number D2665. At the same time the brakes were changed from the Prestall system to conventional vacuum cylinders and V hangers, initially retaining the single large vacuum reserve cylinder. This rebuilt version is available as Comet Models S14BK.
They were not exclusively Southern Region property, with one set each to The Master Cutler, The White Rose, The Norfolkman and The South Yorkshireman and two sets to the Atlantic Coast Express.