NOS carburetors. What issues to be aware of if any?

Found a NOS 2bbl carburetor Carter BBD for my super six. I've had issues with all 3 of the used ones I've rebuilt. I'm thinking NOS should be a good route. What does everyone think? Should I rebuild the NOS carb? Could there be an issue with the old paper gaskets? Accelerator pump? O-rings? Thanks for looking and any help is much appreciated.