Worked on the car a little today. I just made the linkages the same length to start (50mm). Cold, the car starts right up, high and smooth idle then slows after a minute and settles into 900 rpm, still smooth with almost no engine vibration. The chokes open during this time and right before they are all the way open, the idle slows and the car stalls. The car gets harder to start after a few rounds of this. Once warmed the car stalls too often to try to sync the carbs. I pulled the fuel/air screws out and blasted some carb cleaner into the tiny air hole up top and the cleaner jets right out the fuel/air holes.

After putting the linkages back on today, I see a slight dribble of fuel out of both mains. Not a lot but there is some. If I block the air hole for a few seconds, the dribble stops.

I am picking up a gummy set of 72 carbs next week and will get those cleaned up and then can at least have some other carbs to test and learn on and see if they are any better.