The Arrows trailer was built to be towed behind the Bedford 4 Tonner. I agree with Ian - A big Ifor Williams - say a 10x5 will be a lot more practical.
Withams - who flog off the Ex MOD stuff - specifically warn against trying to tow an Arrows with a Landrover.
Could not agree with this more, I had the pleasure of towing one of these with a defender for a few hundred miles distance, (out of UK), pain in the backside, as well as being wider by a fair bit, the nose weight issue coupled with its dead weight made it a pig to tow, did not want to track the rover, trying to stop it was a bit of a giggle, tail wagging dog springs to mind, probably due to hitch height being higher than a rovers chassis. They really were designed to be towed by a specific vehicle, a four tonner, just like the little Sankey was designed to tow behind a rover, also have a high COG for a rover.
Of course an old Rice horsebox converted to a flatbed would be ideal, should anyone be thinking of flogging one . . .