Once more unto Old Mine Road: I went and drove the whole length of it (as currently mapped) today. I am going to propose it be truncated to the junction with NPS 615.
My primary justification for this is that there are zero shields anywhere north of this junction. Can verify personally as of today (technically yesterday in eastern time as it's after midnight).
Secondarily though, as Charlie describes, some of the road is rather iffy. Between Pompey Road and Dingman's Ferry, the road isn't just unpaved, it's a one lane gravel road with a lot of huge potholes in it. Here's a couple photos showing what we're dealing with here:
The section Charlie mentioned that has private property signs had a huge crater the entire width of the road. I had to drive on the grass next to the road (fortunately there was a car's width of grass next to the road) to get by.
This section certainly does not seem to me like something worthy of being mapped as a clinchable road.