For me, it was always going to have to be quite a small affair. When I first started making plans for a layout in my teens I was always conscious of the fact that I wouldn't have heaps of space to build it in. I was quite inspired by some of the Highland layouts that were featured in the Railway Modeller at the time, one of them being "Kyle of Tongue" (Steve Flint, I think, was responsible for that one)
I was always concerned about the lack of variety of stock that I could run but, having seen various photographs over the years, it would seem that there were more types running in this part of the world than I'd originally realised. The Sulzer type-2s (24-27) were all running at various points during my childhood, although I only really (vaguely) remember the 27s. Class 40s certainly made appearances on various occasions, and I've seen photos of 50s at Perth so it's not a
huge stretch of the imagination to think that in an alternate universe they might have made regular trips further north. 47s were standard fare for a time, as were 37s, although they came along much later in the period I'd like to model (70s to early 80s). Having said that, there's much more scope for throwing together a non-matching rake of Mk2s if I was to go for the late 80s to early 90s...
See I'd go Scottish Highlands but the sparse service on the rural lines puts me off really. The Highland Main Line is as far north as I would go as you have (for the 1980s) a generally more frequent service, sleepers, London day train(s) etc.
I sort of agree with this; I'd
prefer to build a model railway where things run largely as they would have done in real life. I suppose it depends on what you want your layout to do; is it supposed to be an exact replica of a specific location, a fictional location with a realistic service pattern, or are you happy to use "modeller's licence"? I guess it also depends on where you want to operate it; if it's a home layout then you can do what the hell you like with it, but if you were to take it to an exhibition and run the wrong train (especially if it's modelled on a real location) you run the risk of upsetting the Rivet Counters!