Gresley coaches were equipped with Pullman gangways and 'buckeye' knuckle couplers as fitted to the new British Railways standard Mark 1 and later coaching stock. As newly built Mark 1 restaurant and buffet cars entered service on principal trains the older Gresley coaches were redeployed to the long-distance inter-regional trains before sufficient stock was available to completely replace them in the 1960s.
However due to issues with the riding quality of the BR stock, particularly the heavy restaurant buffet coaches, the smooth-riding ex-LNER Gresley buffet cars were retained. Serving 'cross country' trains on the North East to South West interregional axis the coaches become the last pre-nationalisation passenger coaches in regular service, being withdrawn in the mid-1970s.