I am not sure exactly what you are saying in relation to the operation of the choke.

Have you check to see what the fuel level is in the bowl?

Did you remove the jets ? If so , are they in the correct positions ?

In answer to your question about the rich condition being cured by re-surfacing the mating surface, the answer is yes.

I also query if you have the little ball valve in the accelarator pump and the corresponding pump discharge needle both in place? If that check needle is missing then fuel can be drawn at all time through the discharge nozzle.

Have a look at these things and make sure they are all there and doing their job.