John,
These are postwar manufacture, going by the labels, the prefix 61BE is a RAF stock number, the part number 7067949 is listed in the QL book as for QLB ( Bofors tractor), crew compartment, front seat cushion. these are exactly what I have in my QL and I would hazard a guess you got them from the same source. There is an asterisk after the number in the book, denoting that part is also used in MW, OX, OY and QL, so the seat is not really specific to the gun crew compartment of a QLB and can be used on all Bedford seats.
regards, Richard