This weekends update:
Comparison of old diaphragm and new
Determined that the diaphragm is supposed to move freely so I would have to grind all of them down. Ground down on left, new on right.
More pictures of the carbs coming apart
Using my new parts cleaner
More clean parts
All 4 carbs rebuild and put back together
Now I have to work on getting the timing belts changed. I drained the radiator and got it unbolted, but I got stumped trying to get it off. Going to have to do some research and tackle this one another weekend.