Here's a diagram - hope that helps. Don't be concerned if yours don't match up exactly and there's always a bit of variation between the eggs. It's amazing how much bigger the air cells get when they draw down just prior to the ducklings pipping internally.
From what I've read Call ducks can...
Until you have external pips there's no reason you can't open your incubator to continue to turn the Muscovy eggs. Skipping a few days while the Pekins hatch won't worry them at this late stage of incubation.
I kept the humidity around 35-40%, then increased it to 75% for hatching when I...