I had a look at your Gif files, very impressive. I thought the resolution on #3 was excellent. I assume the arrow is the direction of the imaginary illumination. I can't see any turned edge, but to see this properly your knofe edge must be much closer to the focus of the edge zone. It will then show up as a narrow very bright arc opposite the knife, much more intense than the light parts on the mirror surface. When your edge is perfect you'll see a very narrow bright diffraction ring uninterupted around the whole mirror when you have the knife at the radius of the outermost zone.
Judging from your two foucault pics, your mirror is going hyperbolic. The shadows were more subtle in the first and very strong in the second. It looks very much like a very fast parabola with the knife at the 70% zone.
Cheers, Mark.