Some more rework, this time a very old ditched road and stream I created for a refight of Lutzen 1632. Finding it in the bottom of a drawer was a light-bulb moment - just the job for Hell's Highway. The ditch was reduced in size and the whole thing textured and painted. The stream has become a canal.
I used the idea from Olicanalad's Games of using woodstain on the water (link) thanks James
Here's a picture of the original game
Obviously I now need to create bridges and more canal sections plus linking roads to Hell's Highway