RE: screws and o-ring for spider diff??
You need to get yourself the right screw bags as spares chris, delivery can't be too bad on small items like that, and you could go for the switch to titanium screws at the same time. IMO you can never have too many screws, buy all the spare screw bags for your car, and you won't have these problems (machine screws or tappers, hex or standard, etc., just get the originals).