1973 Duster: Replacing fuel tank and need some parts

After about 2 months of not having time for my baby, we finally dropped the fuel tank (*) and found it was full of rust chips and orange-brown gas.

I went on Rock Auto and ordered a new tank and fuel sender (Spectra). But where can I get the various O rings/gaskets I need?

1) gasket for the sender (keeping the lock ring for sure)
2) gasket for end of filler neck (at gas cap end)
3) big rubber gasket for filler neck to gas tank?

(*) We used a Harbor Freight motorcycle jack for this and it made it really easy to lower the tank smoothly and evenly.