Round hatch roof holes

[Jordan Baker]

Hi all

Just trying to figure out some of the holes on my Cab13 round hatch roof.

The ones in the red circle, are they supposed to be there?
The ones in the blue circle, I believe are part of the original design?
What about the one with the blue line pointing to it? Its hard for me to tell if it was an original hole as its been made bigger.

The ones in the blue circle I think are from a piece of metal cut in an arch similar to the radius of the hatch. On either side there was two pieces of bent angle. Can someone provide some more info on what these looked like?