1967 Volkswagen Beetle Stalling

Engine Performance problem
1967 Volkswagen Beetle 4 cyl Two Wheel Drive Manual unknow miles

1967 Type I VW Beetle - - Don't know the mileage, since the odometer is not working. I bought this car last week (admittedly, the last time I owned a car this old, it was a new car.) - The car drove nicely on the test drive, and for the first few days.

Now, it stalls at stops (at idle or at stop signs). It starts back very easily, and drives like a dream, but nearly every stop, it will stall. It sounds like it might be something as simple as a carb adjustment. But I was wondering if I need to be doing something different than the regular fuel. Do I need to be addiing a lead additive or some other fuel treatment? I have added two tanks of gas, and so I didn't know. Thanks