Yes, the fuel is coming from the discharge holes in the primary emulsion tube holder. It seems to be 'spitting' rather than 'spraying'. There is no ball below the emulsion tube. The tube is sealed at the bottom. I attached a picture. There was no ball in either carb or in the 'parts carb' that I have. The rebuild document on mbzponton.org also mentions finding no ball.
Mercedes-Benz Ponton Solex Type 32 PAITA Carburetor Reconditioning © www.mbzponton.org
I started with the idle mixture screws at 2 turns and I had them out to just over 3 turns and no difference.
The car would not idle well before the rebuild. It hadn't run in over 3 years. I could get it to run with the choke and both carbs were leaking fuel from the accelerator pumps.
I think the issue is the 'spitting' of fuel from the primary discharge is causing it to run too rich and uncontrolled. But I don't know what is causing it. I lowered the fuel level and it didn't fix it.