For project Launch Rover to get my boat in the water I have blagged a set of tyres off a Manitou, but they require the above size rims. Used to own a 101 but can't remember if the rims on those were any larger than normal. Can you get 20" rims to fit Landie hubs, I'm not too worried about the tyres hitting the bodywork as I don't intend to have much.
Cheers