In 1933 the Derby Carriage Works of the LMS built a batch of fifteen sleeping cars to lot 699, diagram 1863. At 65ft in length they were the longest eight-wheeled vehicles built by the company. The interior of the 37 ton vehicles consisted of seven four-berth compartments and an attendant's room. Of LMS 'Period 3' design, these were among the last turned out in fully-lined livery. In December 1963 No. 592 was withdrawn from passenger service and used by British Railways staff as a dormitory coach, with Departmental Number DM395922, but remains substantially as built.

It was purchased by a QRS and GCR Coach Group member in 1976. It arrived at Quainton with other stock by a track slew of the BR line in July 1977, for details of stock arriving in this delivery see the Visitors section. The carriage left Quainton in 1991 for the Llangollen Railway. It is currently in use as static volunteer accommodation.

Reference:
Good News from the C & W - Quainton News No. 29 Autumn 1976
A Century on Rails - A Sequel to the Stockbook - Trevor Page - Quainton News No.59 Spring 1986