I think you'll have trouble finding 750x20 traction tires, at least we do here in the US. Steer tires are available. You can find 825x20 traction tires which might suite you fine on the rear.
Mike B
Coker tires has a good selection.
Universal Vintage Tire is also a great selection.
Pretty much all non-modern pattern 7.50x20s are made by one place in Pennsylvania:
http://www.stausaonline.comEveryone else is pretty much a reseller
