Ian, it seems you have dealt with the most suspect items. I concur with Dave that the main items to rule out now are the Hubs, spindles bearings. If it were me I would fit new wheel bearing kits both sides up front cleaning the hubs thoroughly. Then carefully test the run-out on the hub itself first – then the rotors after. Also re-check the lower balljoints and tie rods carefully for wear. It sure sounds like an issue with the front hubs / brakes when re-reading the posts above.