Cutouts went much easier than I anticipated. The corners remained attached and I went back with a hack saw blade by hand and extended the cuts into each corner. Filed all surfaces, scotch brited the edges and used a mini round file to relieve stress in the corners ever so slightly. The trays snug up just right. Here I have them propped up with my wallet . Might as well. My wallet is on a first name basis with them. I am extremely pleased with how its going. My angle Dremel cutter started acting funny so I have to see why it does not engage, and then I will cut out the other Skyview. After that I will put the panel in the airplane and fit the two panel ribs and center stack together so I can mark for attachment holes.
I cannot push the GTN 750 tray through the opening. Its VERY close.
The PM5000 tray sits in the opening exactly. No extra space.
The SL40 tray just starts into opening. Its all good.