643 is a Gresley buffet car built at York in 1937 to diagram 167. It was one of six built for fast five coach Liverpool Street-Cambridge services, and survived in BR ownership until 1977.
It arrived on the SVR in 1977 and saw service until being withdrawn to be restored to original internal condition in 1987. Just before withdrawal, it was one of the coaches used in the filming of the television series Hannay.
643 is owned by SVR(H).