Had another thought whilst I was working on the car tonight. It occured to me to check the fuel level in the fuel bowls thru the built in sights on this particular model of carb, and I noticed that they are both pretty high- particulally the secondary fuel bowl. Of course, I will reset these to the correct level, but I was wondering if this could have been contributing to the excessive idle speed.

Will find out tomorrow when I set them to the correct level, I was just wondering.