The only other thing I can think of, is that is is on an Ex MOD truck and it was a containment can for 90W, or something related to Bomb Disposal or other branches of the RAF usages, or Royal marines. My Ex Mod truck was adorned with Red Fenders, and strange shaped brackets in the back tub. I can assume from pictures that some bomb disposal units had red fenders, and that the brackets in back were used to contain specific hardware or tools they used. REMLR.com is a very good source of Military Rovers, from Australia.
cheers mate,