Just noticed that some 7.50R / 16 Rangemasters are 7.50R/80 /16 and some are 7.50R /16 which suggests there may be 2 different aspect ratios around. Make sure they have the "R" as this is a 7.50 radial, when your series was new they would be 7.50 / 16 crossplys, they should all be long gone but occasonally old stock comes up for sale, avoid it!