I mean Black Scars as well, but I was specifically referring to Sea Wood Scar (https://www.openstreetmap.org/way/1299232863) when looking at the single rock 150m away on aerial imagery. :)

I understand what you are trying to achieve, thanks for taking the time to add this detail. It’s tricky to interpret old maps!

If you’re uncertain about the shape of things, I suggest it’s probably best to represent them as a node or way, rather than an area, and then that uncertainty is represented in the mapping, rather than a false accuracy coming from using an area.

You might find some more information on geograph: I can’t find anything for Black Scars or Sea Wood Scar, but Wadhead Scar comes up with some results (https://www.geograph.org.uk/search.php?i=211699742) which could help refine that.