Well, the rotpot carbs always seep a bit around that gasket. I would check the mixture by reading the plugs. If they are black and sooty then you are too rich. I don't remember if right or left on the flywheel is advanced, but the distributor advances by rotating counterclockwise. The points should be 0.019" new, and 0.016 used. (I actually like 0.013 better for more dwell)
The rich condition may be caused by a sticky or faulty power valve in the carb, sometimes they are not rebuilt overly well or they have weak springs. You need to be somewhat familiar with how they work to test them. The little screw on the carb is the idle mixture screw. The best way to set it is with a vacuum gauge connected to the wiper port on the manifold, just adjust it for maximum vacuum at idle. If you don't have a gauge, turn it in (lean) slowly until the engine starts to lope or stumble and then turn it out 1/4 turn. If it's too far out it will idle too rich.
