I ran the GNR on Sunday and on the start line had the "Local Hero" theme song in my mind which was very motivating (no ipod on!), but as soon as I crossed the line it went out of my mind haha, ended up humming a James Bond theme song instead for the first few miles then talking the general randomness with other runners as you do!
Hope you enjoyed Wolverhampton, I looked at doing it last year but it's tended to clash with the late September/October marathons/training.
There was a successful thread on this a few years ago - someone simply ran the organisers and asked. It'll be around on the forum somewhere if you have time to look. The numbers were basically something like 20,000 ballot, 10,000 club/GFA/sponsor's and company partner's places e.g. international tour agencies, and the remainder (up to 10,000) as golden bond.