To: Werdigo49
In answer to your comments and questions sequentially as possible:
The dashed lines in black are old established routes that were old drove paths, or cart tracks going back over centuries. They are not what we would recognize as trails like we have that were established for hiking. There are virtually no trail signs or blazes on the ground except on National Trails or "ways" like the West Highland Way, Great Glen Way, etc. Often and probably usually these dashed lines are still used for access by pony or ORV to access deer hunting "stalking" locations. Deer stalking is big business in Scotland and many large estates derive much of their income from this activity. Also, deer are managed as an industry much as cattle here in the Colonies.
When a dashed line ends on the map, so does the dirt track that it indicates. After that you hope for some signs of human passage. I say human passage, and not what the Scots refer to as "deer or sheep trods". These trods look like they are paths or the trail, but are not. A clue would be that a trod leads in a direction that makes no sense to a human walker.
Occasionally you will see a tiny cairn alongside the trail. They may be placed in locations where another trail splits off, but not always.
Once I was walking along a cliff top in the Highlands when I happened to see a tiny pile of maybe fifteen rocks on the edge of the cliff. I walked over to see what it was, and found a narrow path leading down off the cliffs into the valley below. As I was just out wandering for the day I took the rather sketchy narrow path down into the valley below to make a really fun loop hike. To give you a bit of practice, it was at NN19271 65743 and took me around Binnein Mor back to my trail. One of the things I like best about Scotland is that you can often see an entire days trail from above due to the terrain and lack of trees and brush.
As far as sections of the route missing from the maps you have, I suggest picking up some map quality paper and printing them from your CD. Just don't forget that inkjet inks are water soluble. I have printed on hand cut Tyvek sheets in the past, but not with a laser printer although it is probably possible.
The MemoryMap routes can be exported to your GPS, but not the actual maps. I highly recommend this MicroSD Card for GB Scotland. It's the one I carried.
https://buy.garmin.com/shop/shop.do?cID=255&pID=13764
I know, it's another $140 expense, but I believe its vital. I carried both the maps, and the GPS with the chip. Used both extensively. Since you will be not meeting many people on the route it could be a safety issue.
The Magnetic Declination diagram on the Ordnance Survey maps is only for showing the relationships between Mag, Grid, & True it is not to actual scale and cannot be used to set your instrument. Depending upon your map sheet, it varies from 4 to 5 degrees West of grid north with an annual change indicated on the map. I carry a bearing compass that lets me set the declination with a small screwdriver attached to the cord. So far it has never been out of my pack.
Your last question and thanks for you comment on my Blog. My CWT hike was May 4 through May 17 with another week or so when I hadn't had enough and added the West Highland Way for the second time. This time southbound. Returned home on the 2nd of June.
This year I will be going for basically the same time period.
Oh, one more thing: This may seem a little strange but years ago I was taught how to clean my cooking gear in the Highlands by a really old Scottish long distance hiker. In the wilds, the peat is highly acid. You simple take a little water and a handful of peat moss to scrub out your pan and utensils. Then scoop up some water from the stream to wash out the remains which you then toss away on the ground away from the stream. I do it and it works just fine. Away from civilization however. He was the same gent who told me; "ya dinna need to put those chemicals in yer water laddy. Just tak yer water from the small burrns, not the big uns. The big un will likely have a daid sheep in it up on the hill".
TW