Interesting that Tony should mention teaching at schools backing onto railway lines, since as a lad I attended a primary school that backed onto the West Coat Mainline. This time period, the mid to late 90's, was probably the last time there was any real variety on the railways. 20s, 31s, 37s, 47s, 56s, 58s, 60 and of course the coming of the 66s and 67s. Not to mention all the electric types and DMUs.
And the liveries! Trainload Freight, Railfreight Distrobution, Royal Mail, Intercity, Regional Railways, 'Dutch' engineers livery, Mainline, Load Haul, Transrail, Virgin, Freighliner, EWS, DRS, Fragonset. I'm sure I've missed some, but all those liveries could be seen running concurrently at that time. No train was ever alike. It's most certainly a time period I would love to model one day, once I have the time, finances and space to do it justice.