More news…… I called Longstone Tyres (they supply Classic car tyres in general). They told me that the Avon Rangemasters are still being made in the UK and most are supplied direct to Vintage Tyres. So I spoke to Vintage Tyres today and was told that the Rangemaster is not only a radial but is huge, heavy and intended for the power-steered Defender and not suitable for the Series Land Rover. He recommended the Traction Mileage 700 x16 Crossply, as originally standard equipment for the Series. I am going to take their offer of four tyres with free tubes. Good deal and they really look the part.