These are sweet, Ken. In the 80s I took a tour down the Molly Kathleen mine, west of the Springs in Colo. Nine of us lowered in a cage 40" square, down 1600'. You could feel each other's pulse. On the ride back up, the guide said: If all goes well, we'll be back at the surface in about 70 seconds. If they don't, we'll be back at the bottom in about three seconds.
Those marks are a bit of a mystery to me. They look like film burn here but not so much so on the negative. I will need to work on them if I decide to print this one