[Ypahihi]

I had 2 attempts at this before finding something that worked and I was happy with.
Had issues with finding a hinge to match. Ended up using a heavier grade 100x75mm hinge from Bunnings. Used the double barrel side and cut the excess off to match the plate. Made the plates out of an old perspex window. Used what I had.
After the 1st attempt with the thinner hinge, I didn't like the how much material was removed when you drill it out and went with the HD hinge.
I made allowances for the plate and the key way when cutting the slot and set the plate roughly 2mms into the barrel. This allows the key way to sit snugly between two surfaces without the chances of the key way rolling against the smooth bottom of the hinge when in rotation.

If it's any help when you cut into the Jeep to get to the blend doors you only need to make TWO cuts. A horizontal top cut and left side vertical cut. The other sides are part of the two piece housing. Pop off the metal clip and wiggle out the whole piece.
Makes a neat and tidy install using 2 lengths of tape to cover the cuts.

Still working without any issues.