Custom JD style wheels to go with the 520/85R46 tires available here:
R1 - standard tread tires:
https://www.shapeways.com/product/3GRFMN6SP/1-64-480-70r34-r1-x-4-tractor-tires
R2 - deep tread tires:
https://www.shapeways.com/product/DACMF74B4/1-64-520-85r46-r2-x-4-tractor-tires