The route is pretty convoluted which I assume is deliberate to collect as many climbs as possible.
Not quite. Nik wasn't interested in the climbing, just the mountain roads. His method of calculating AAA was to think for a moment, then say "I think that's worth a couple of points. Don't you?"
Another excellent 300 of his was the Drove Roads of Mid-Wales. (I wonder if I have a routesheet somewhere).