Brian,
thank you for the photographs. They tell a much more complete story.
studying the photo with the distributor it is quite clear the distributor is so tall that it actually blocks the U channel, below the window gasket, that the three engine screens are supposed to fit within
I have learned the center engine screen has two versions, and the early/late versions attach to each other in a different manner. But I have never confirmed if the forward to rear lengths of the covers remained the same, or changed with the new center section
I suspect the lengths were not changed, which would mean the side covers could interchange, with the understanding that their attachment to the center screen may differ and involve drilling correctly located holes for the screen center section which is attached with screws
how about you remove the distributor cap, and/or wires, and be careful to note which wire goes where
I think we will find the side covers will properly mate to a full-screen center section
🤞🤞
Larry