If the eyebrow window is the solution, gotta wonder what the question was.
I've owned and driven a number of planes with eyebrows, B737CL, Westwinds, & Astras... They give a nice spot to put a tracker system in without chopping new holes in the pressure hull. Otherwise, keeping the sun shade in place is the main justification for what they do. Even in close form trail they don't get used.
The question was; How can it improve cockpit visibility by eliminating four windows that were there as original equipment? When they were converting DC-4s to tankers they would often install an eyebrow window for the very purpose later described by Checkboard.