I counted the segments on the hinges and they seem to match up with the prop. 8 segements in total.
As far as the 4 bumps go, those are only found on the fly boxes which have the fly holders riveted to the box itslef. In the above pic, the box pictured at the bottom has foam fly holders which aren't riveted to the box.
Also notice that the bottom box has the rivets positioned on the sides and top center, in the same place as the screen used prop.
The top lid also doesn't have the lip (just like the original prop as well)
Regarding the center knob, you could probably use this -
Model number - KN-3412
Just remove the top silver part and file down the top, and then file off the skirt around the edges.