[HandyDandy]

First attempt at posting image.

[Windflier]

Handy, I think you may have solved the mystery.

If that ring with the phillips head screws embedded, ever pressed into a soft surface, you’d expect to find the sort of impression we see in the NASA image.

Good job!

[T. P. Pole]

Yup, I think you got it. That head at 9 o’clock is a dead ringer. Good job.