Time to rebuild?

I have the Holley 1945, and the gasket is about 1/4" or maybe 5/16" thick. I get what you're saying about the gasket affecting the choke operation. However...

Yesterday on cold start after work (ambient temp 55 degrees) I tried pushing the choke closed with my finger as well as open. Closing it made things worse. Opening it didn't make things better. I suspect the choke is working fine and either there's some non-choke-related problem or my expectations for smooth cold idle are too high. This morning I tightened the fast-idle screw another half-turn, and that may have improved things a bit.