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 In December 1963 No. 592 was withdrawn from passenger service and used by British Railways staff as a dormitory coach, with Departmental Number DM395922, but remains substantially as built.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.

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