I decided to make a ramp for laying inside the fuse over the spar box since I would be squeezed under that area drilling the inside skin on the door.
I removed the door and deburred all the parts. I cut the lock hole which is not pre-punched in the older kit I have. I usually take the distance between the flats and drill a hole in location that is about .010 less than the flat distance. Next I file the flats to fit the lock, and then using dremmel and perhaps a nibbler get the two end radii cut and fit to the lock. The lock fit was great without much slop.
I dimpled, countersunk, and cleaned and prepped the parts for priming.