Well, if I were the sort of person stalkers found interesting, all my red flags would be up. I’m not, but we mostly didn’t know that.
That said, you did a pretty good job. Thinking about the direction I was facing and how far they seemed to be, though, I would bet that they flew directly over the airfield you pointed out. But they weren’t landing there. They would have been descending already. I bet when I lost sight of them they were actually beyond the airfield. Of course, they would have been heading south, and if they wanted to approach from a direction very different from north they would have had to circle around.
I think they were not Ospreys. I actually got to see one of those just last summer, from a roof deck, when it landed about a quarter mile from our vacation rental. Ospreys aren’t long and tapered toward the front. The speed of these craft? Hard to say, as it wasn’t clear to me how far away they were, but I would guess they were going quite slow for an airplane, probably less than 100 mph.
They could possibly have been the Lockheed QT-2PC, but only if those can fly backwards. The vertical stabilizer leaning forward on the leading end would have been the distinctive feature.
The more I think about human powered aircraft, with their enormous and slow turning propellers, the more this idea seems to match the propeller I could barely see turning. However the rest of these aircraft seemed too chunky, and the speed too high, and the probability of seeing two visually identical ones flying such long level routes on a cold and fairly windy January morning without any fanfare, all argue against this idea.