Thanks for the responses.
I was hoping to avoid starting from Glenridding hence my specificity around the old coach road, I’ve not ruled it out though, and definately want to bag the descent via Dollywagon.
b r, the bridleway you refer to, did you take the one from Mariel Bridge (NY350226) or Groovebeck Fold (NY373221)? The former can’t be found on Google Earth and the latter can for the most part. I’m just hoping to avoid attempting the latter if it’s less apparent from the ground than it is from the sky. I think I’ve stood and looked for the former previously and it wasn’t at all obvious.