It's worthwhile remembering when looking at OS maps that the green rights of way, both footpaths and bridleways, may not actually exist on the ground. What you should actually be following are the faint black dotted lines, shown on the OS Map legend as 'Path on the Ground' as these paths will be the ones that you'll see for real.
If you look at the area around Scale Bridge, on the map, you'll see the dotted black line about 100 meters south of the bridge and how it snakes up hill a bit towards Scale Gill, before branching off to meet the right of way coming up from Wha House Farm.
I teach navigation in the Lakes and most of my students are surprised when they learn about the black dotted lines, as they automatically assume that they'll be following the green rights of way. Once they know this fact, navigation in the Lakes becomes a lot easier.