Here is LCGB photo 1966 on the internal views of M24449M a BR built Driving Trailer with the BR side LHS window (none of RHS) Any LMS Driving trailer would not have the side vehicle and from memory of cab rides in early 1960s the hand brake was more central and i dont remember the central window having the ??? Brake controler if thats what it is,, Can others interest confirm what they think controls are which i think are Left to Right ?? regualtor, ??sander?? Vacuum on window Electric Horn, Hand operated Windscreen wiper, Hand brake in the foreground by the adjustable seat or in the central controler the regulator?