RE: wheels
Seamus, drilling and bushing the hub is only an option if the hole was drilled or molded off center in the first place. More likely the tire was not installed correctly and it's sitting askew on the hub.
Fredsaidno, if it's glued on like many foam tires are then you can either live with the runout or chuck the tire in a hand drill and use some very coarse sandpaper or a power sander with the tire running against it to reshape it and true things up. A light touch goes a long way if you do this. Also sticking the wheels in the deep freeze overnight will stiffen up the foam and let it cut better while still cold. Work fast as it'll warm up and get soft again pretty quickly.