Bill,
I know you didn't ask for welding safety advice, but since you state you had minimal practice and experience, I thought I'd throw this out.
Make sure the wheels don't have any tires on them when you weld em up.
Having read this, I'm sure it sounds so logical it's silly, but a good buddy of mine almost lost an arm and half of his face making a "quick and simple" repair on a garden tractor or small trailer wheel. The additional tire pressure from the added heat, blew the tire and wheel to bits.
Up until that happened, I can't say I would have thought about it.
