I am trying to keep me restoration on my early Rover Ranger as original as possible. I need to know where can I get new tyres from. The originals are a square shape, ie, looking at the tyre from the front or back of the mower coming from the rim the sides are vertical and the ground contact face is flat. All I can get at least locally are tyres that are meant for a wheelbarrow which have a rounded ground contact face. The front tyres are a 4.10-6 and the rears are a 4.00-8. Does anyone have any ideas ?