The exemptions in force for both NYMR & Vintage trains refer to "Hinged Door Rolling Stock". This is defined in the document thus: “Hinged Door...
Today's formation is 45212, Mk 2, Mk 1 RMB, Mk 2, Mk 1 BSK, Mk 2, Mk 1, Mk 2. Effectively, each Mk 1 is sandwiched at either end by a Mk 2...
Separate names with a comma.