This is just a thought, but after reading through the posts, there are quite a few who have reflections in the "rear view" mirror, but none on the gauges. I noticed that when flying straight and level or even in a bank, many times I don't see anything in the gauge faces either. If you look at the images I posted at the beginning of the thread, several of them were at extreme bank angles or inverted. . . .one, while I was sitting on the tarmac, I had to slew in a circle until I got what appears to be the edge of a building or roof overhang, otherwise I wouldn't have seen anything either.
Just wondering if maybe some of you might actually have reflections, but just haven't been in a position where they will show themselves.