After we had agreed on a design, the first task was to create a "frame" for the doors that would exactly fit the irregular stucco arch. I taped some paper to the inside walls and marked out the interior edges. I built the uprights from old growth Redwood and the four curves with Alaskan Yellow Cedar. I cut fingerjoints in all four pieces, held them in the place, glued them together and lagged them to the stucco.
I made the door sone at atime. Allowing for the fact that my frame was 3/4" of an inch out of true from one side to the other, I hung the first door with a 3/8" variance up and down, hoping that I would be close to square with the other door and wouldn't have to move the inhiunges too much. When it came time to hang the second door, it fit beside the first door perfectly flush up and down with exactly 1/16" gap between the two door edges. I have hung a lot of much simpler doors and never been so lucky. I very nearly cried with joy and relief. I certainly jumped up and down and yelled.