This plan was created (and printed 44" square!) for a meeting in March 2012, though I have removed some of the information that is now superseeded by articles on this site. On it you can see the basic route of the track, coupled with "photographs" of the route at various points.
Single- or double-lines for the track do represent the real route being single or double track at the time of the model, though the track plan at this scale is pretty representational!
To see the plan as big as possible, click on the thumbnail here, then click Download Original on the lightbox to get a 1920px square version.