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? Thanks for looking and any help is much appreciated.

How much are they asking for the nos carb ?