Perry,
You make me work hard to dig out my nodged dutch oven covers. Yes, the c.1930's No.8 do cover fits pretty snugly down on the pot when the lid is upside down. The nodges only go to within about 3/16" of the edge of the cover.
But on my No.7 c.1920's slant TM Tite-Top Baster cover the nodges go out to the edges of the cover and, when inverted, the cover rests about 1/8" above the pot.
I probably shouldn't have said "to prevent condensation" and, upon thinking about what you said, I guess that's not right. But one is not supposed to store do's with the cover on tightly. Why? To prevent rancidity? A cover ajar works fine but the cover might become un-ajar and, thus, seal the oven which is not good for it. Of course an upside down cover will not usually seal as well as an upright cover.
I guess I'm at an impass as to what the nodges are used for. My big dictionary doesn't have 'nodge' in it. You must have a HUGE dictonary to have found that word. What does it mean? And if you can tell me it's a real word I'll be surprised but I like it.