My records show this is a Bedford J4 with Miles bodywork, one of six supplied to the Hertfordshire Fire Service in 1955. It is very likely that it is an Bedford A-type rather than J4 (anyone?). It was stationed at Much Hadham for some of its service and possibly also at Stevenage. It was in preservation in the late 80s at Rickmansworth and I believe was later re-registered FSV 686. I seem to remember it was damaged - does it still exist?
Spot on Aj! The A6 was a very common chassis and much loved in the forces as a "one tonner". Bedford chassis always seemed to make a brilliant base for fire appliances, more than can be said for some of todays offerings.
With reference to the first comment about this vehicle, I am the owner of PBM 609 that has damage to the N/S front end and n/S roof above door, possibly mine you are thinking of?
Added by Simon Rowley on 19 December 2009.