Looking for more answers Carb and mixture control

It  took a while to get it all in order, but it is back together and on the Coupe and it doesn't leak.  A lot of reading and measuring...

Replaced needle and seat and gasket set no more leaks for now.. Pretty simple carb.. but not cheap..

Sounds like needle valve and seat, as you suggested.
You’re on the right track.

If I am overworking my welcome here I am sorry.  Issue:  The Mixture Control on the carb was wired shut when I got the airplane in Feb of this year.  The other day I noticed a drip coming out of the throat of the carb when the main fuel was turned on.  I talked to an A&P, he looked at it and told me to pull the carb off.  I have a follow up appointment with him Mid July.  I am thinking of replacing the needle valve and seat.  And while the carbt was off I took a look at the Mixture Control.  The top half of the Carb has a model #NA S3-B.  From what I have read that model does not have a mixture control.  The numbers on the lower half of the carb are #380174, again my understanding is that is a NA S3A1 and this carb should have mixture control.  Well this carb does have mixture control.  From the looks of it, it should function perfectly fine.
By the way the plane has run great for the few months that I have been flying it.  I am sure the fuel leak has been there since day one and just  went un-noticed. Once the main fuel valve is turned off no leak.  So when we were flying I am sure there was zero leak and when stopped the fuel bowl would fill and leak out the throat of the carb.
I am looking for you thoughts on repairs while it is off and I have an A&P to put it all back in place.  I am certainly not an A&P but this carb is really pretty basic (other than it flies-a real big deal).  I am just trying to do things right.  
Here's hopin' for help.

Thanks,

Ron