Hi Tim,
Im not too good with carbs. I think theyre a little wacky, myself. Anyway, the order should be gasket, insulator(plastic thing), gasket, metal shim, then the carb. There should be only 2 gaskets there. And be sure to always have the metal shim there, or else the car wont idle.
As for your other concern, someone more experienced with carbs should tackle that one.
Rob
66 SDV