Thanks for this info, especially the tip about the Edelmann cabinet. Very cool ! I think I now know that the fuel line should be 5/16, and I also know that the carb (Carter W-1) threads are 1/8 NPT. In my local Edelmann cabinet, lo and behold, there's a fitting with 1/8 NPT male on one end, and a female flare end for 5/16 tubing on the other.

Thanks again,

Alex