Many thanks to you both will let you know how I get on.I aggree with everything that Parksy says and have owned and towed with SWB Paj/shoguns for several years. I am getting the same sort of MPG on my petrol 3.5 GDI albeit a more modern car.
My advice would be to get the best available and if buying direct from auction or importer go for the highest Auction category you can afford.