Inner cooler functioning doors.
I saw this on PJ Ash's P-47 so I'm putting them on mine.
This is a 'design as you go' plan so I'm 'winging' it.

pic 1:
I had an old TF GS Corsair cowl so I figured it make some good inner cooler doors.

pic 2:
The dry fit seems pretty good.

pic 3/4:
The cardboard template.

pic 5/6:
The 'final' ply tray.
I elongated one end to make sure I have enough room for the servo (can cut excess off, later).
I also had to make triangular cuts on each side to get the tray into the fuse and past the one former.
To make it light, I used 1/16" ply and will re-inforce where needed.
Looks like the two pull-pull cables for the tail wheel is, fortunately, low enough so they don't interfer with the servo!
The two rudder cables are high but they are wide enough to clear the servo.

pic 7:
The door width is 4" wide so I made a 3 1/2" radius arc and made an A'-B' line that is 4" long on a cardboard template.

pic 8:
Putting the compass at each end of the 4" door opening, I put two 3 1/2" arcs so they would intersect on the tray.
(pencil 'X' just left of center in picture).
This is the rotation point for the doors.

pic 9:
To make the door 'stick out' some as it does on the prototype in the open position, I shifted the rotation point about 5/16" from point C' (center of radius).
Closed position.

pic 10:
Open position (end of door 'sticks' out of door opening).