Larger map here
Following on from the previous post, this shows two different suggestions of cycle routes from Falmouth to London. The blue line is taken from Bike Route Toaster, and the black one from Open Street Map.
Bike Route Toaster seems to be chosing the more interesting way for the final leg, but I don't have time to compare them properly at the moment (I'm supposed to be working, but I couldn't resist experimenting). I will take a proper look later. Meanwhile I would be interested in comments from anyone who knows the areas they pass through. The Bike Route Toaster route is 277 miles, and the OSM one is 447.02km (278 miles) - so not much difference in total distance. (This is the OSM "recommended" route. The "shortest" route is about ten miles shorter).
I don't have a map of the original route, but according to Wikipedia it went from Falmouth through Truro, Bodmin, Launceston, Oakhampton, Exeter, Honiton, Axminster, Bridport, Dorchester, Blandford, Woodyates, Salisbury, Andover, Overton, Basingstoke, Bagshot, Staines, and Hounslow to the Admiralty, and was 271 miles long. It sounds like a bit of a mix of both of these.