motorised caravan hitch drive (Sawtry PE28)

Having returned to owning a small folding caravan moving it around is getting more difficult now I have reached 82 and a bit years of age (very important the 'bit') a motor hitch drive will allow me to move the small caravan around when parking it. I know they are like Hen's Teeth for free but I do have hopes someone may have such a thing unused they could pass on to me. John (SAWTRY)