Revell used to do a ground equipment set which included a RAF Trolley Ac and an oil trolley, but they seem to be out of production - you might find one by trolling through web-sites where OOP kits are sold, or maybe e-bay. However, it's quite easy to make one, using suitable wheels, plastic card or balsa, and stretched sprue or plastic rod.
The fuel bowser in use at the time of the BoB was normally the Crossley, of which no kits exist in 1/48th scale, although there was once a 1/76th or 1/72nd resin kit some years ago. This would have to be totally scratch-built I think.
However, I think there is a white metal, or perhaps resin kit, of the three-wheeled fuel tender still on the market, although I can't for the life of me remember who makes it!