Thanks for the feedback and advice
@Topological. I no doubt have a long way to go yet to create the ultimate image - I've realised that you develop this stage-by-stage. Firstly you're amazed at the atmosphere portrayed, then you start to try to control details, then you start to make the picture tell a story. Another one for now then I must have a break to get other things done, but I'm sure I'll be back.
The trouble with getting absorbed with university and work meant that I missed a whole chapter in our local rail network, one that seems to have also passed any other photographers by. The local branch to Delph (the service on which was part of the Oldham to Greenfield service and known as the Delph Donkey) didn't end, but it was reduced to a very basic branch. GMPTE eventually subsidised the service but it was so hopelessly unremunerative that even a two-car Pacer was too much so they devised this single one known as the Nodding Delph Donkey. As the line was "one donkey in steam" there was no issue with trackcircuit activation, I imagine special arrangement were made for the short stretch from Delph Junction to Greenfield Junction.
I didn't know all this and have deduced it based on AI producing this single car vehicle when I asked for a two-car one, so it clearly knew better than me! I've had to piece together the back story...
I understand the local platelayer had a Hornby three-rail train set when he was young and thought that was normal.