When we first passed by the area where we expected to find this mark, men were working on the utility lines nearby. We continued on and decided we'd come back to it later in the day. After our other attempts, we came back by the spot and found that the men were gone.
This one looked like a slam-dunk! There's a high ledge or outcrop just where the description and topo map coordinates specify. It looks like the perfect spot for a benchmark. I was really shocked that I couldn't find anything on the massive outcrop, nor could I find anything on some ledges I found a bit deeper in the woods. This mark is almost certainly still there, so we will need to bring our metal detector and something to scrape with when we come back. The ledge is heavily covered with moss and lichen that may be concealing the mark.