I emailed the link to this and your site to my friend John Thompson who wrote The Green Machine book all about AFS vehicles.
He came back with the following details, which I hope may be of interest: "Its an interesting Vehicle (JJD231D) Chassis No: Bedford RL 49022, one of the very late (1965) registered Home Office AFS Vehicles. It was built as a Hose Layer and was allocated as part of the Northern Ireland Emergency Fleet (Fleet No:37) and was in store at Marchington as part of the NI Fleet in September 1998. It was at Witham Sales in March 2006 and was subsequently sold."
Scott