I have amended my RwGPS plot: https://ridewithgps.com/routes/28872782?beta=false
Just looked at that, some notes:
- Scout hut is at the Heyhouses lane end of the road you're starting on, shortest route likely to be inland to Poulton-le-flyde rather than up the beach, there's plenty of time to have a run in with weegies later on in the ride.
- Entrance to Gretna services is difficult to spot (not signed), and what's worse on exit you have to take the route signed "South" from the car park just to mess with your head (well not really, motorway services with direct access/egress of the motorway aren't meant to sign the Service/NMU roads), probably worth adding to the route.
- Stay on the B7076 at Lockerbie rather than go through town
- I took Stra(tha)ven road out of Lesmahagow on BGB last year, I'd hope Scottish water haven't got 6 sets of traffic lights on it this time, otherwise it was all right.
- There's an odd loop at EK, the less time spent there the better so...
- On BGB riders that went by EK instead of dodging it found decent cycle tracks alongside the main road that aren't on the OSM map
- Location of Paisley control may completely change approach route as when I was playing with Google it had a different suggested route for StJames, Canal and Gilmour Street.
- Route at Foyers on return from Inverness looks interesting, seems to be the longer and steeper option
- Return route goes down Fort William "High Street", The No Cycling restriction is policed, it's a dive anyway.
- A82 Crianlarich Bypass is mapped, if there is a control there then need to take the A85 and come out on the old A82 route by the west side of the station, the shop and hostel are on the road up the east side of the station, café can be accessed by either, but you're going to have to be quick to catch it unless they've decided to open on the Sabbath.