Collett's distinctive bow-ended coaches were developed from a pre-production series of 3 lots , being introduced from late 1925 onwards. Originally formed into six coach sets formed from E127, C54 & D94, or E127, C54 & D95 diagrams, later sets were marshalled into eight coach all Third Class rakes comprised of C58 & D104 diagrams.

Due to comfortable and smooth riding, the type lasted well into British Railways' service, the final examples being withdrawn during December 1962 and January 1963.

For further reference on the Collett Coaches, see Great Western Coaches 1890-1954 by Michael Harris.