[QUOTE=rgnprof;4263497]Think I got things figured out (Knock on wood!). I had forgotten that I had fiddled with the mixture screws when I started having troubles at first. I reset the mixture screws to 1 1/2 turns out - made it leaner- so far no smoke. I checked the accelerator pumps and they were working but I adjusted them a bit to better shoot fuel down the barrels properly. Choke flaps are ok.

Once I made these adjustments, car starts and runs much better. Maybe better than it has for years...Thanks for all the help![/QUOTE
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One way to adjust those Carbs is to have tools in hand ( screwdriver ) with the air cleaner removed and take the car for a drive to clean out the maladjustment resulting / Motor completely warmed up stop and adjust / Drive some more then stop and adjust > You may have to do this several times sometimes over again until the Adjustment has settled and totally stabilized / Once this is done upon a Longer drive say 25 Miles you may need just a slight adjustment still / Once they are right they well hold adjustment just fine if the Carbs are any good / Note with Motor running and a water hose on low outside you can run water all over the Manifold and carbs Vacuum Lines and find Vacuum leaks very easy. :
Check out the "heat Risers" Closely > see if they are both free with Spring's intact ? or not> most often The Exhaust blows out past the rotating shaft and the Manifold's worn bushings leaking Exhaust making noise
When the case I make a 1/8 plate with drilled holes unbolt the upper and lower Manifolds and Remove the risers completely , you must tap out the Shaft holes and block off W> Bolts / Warm up 3 min extra all good and the Motor Now when warm runs BETTER then " With Risers and now Quite no EX Leaks .
Many of that Year Mercedes like a more ING advance > Retarded you will experience Hard cold start as well as Backfire / Try as experiment 5 or 3 Deg more advance / Mark current Timing mark < Paint Dot > and a second New Dot and try / Cam Timing : are marks on the Cam you Can easily check Valve / Cover off with TDC on Crankshaft you will see Slash Mark " Behind the Cam Gear ** " on the Camshaft " ** ( if Not seen turn Crankshaft 180 degrees Clockwise to TDC again ( top dead Center) to find slash mark / If it not straight up the Cam is retarded ( Very Common ) Offset Key is the fix if needed unless just the Chain is worn out