Hi Mike,
Thank you for your reply. I'd seen the link you sent a little while ago but I must have skipped over the text.
''The model is almost certainly a demonstration model taken to various industrial sites so as potential buyers could see all its functions in steam.''
This rings true for the part I have as;
1. It does not appear to have any parts made from castings, so it's probably not a commercially available kit or toy.
2. Some of the parts appear to have a 'ground' finish which, although not impossible are unlikely to have been produced by a scratch-building enthusiast.
3. It just doesn't feel or look like either of the above.
The demonstration model seems most likely to me which also, unfortunately, means it's probably a one-off and it's extremely unlikely that I might be able to re-unite this part with any of the others.
If someone sees these photos and remembers a box in their attic or shed that contains similarly constructed/ coloured parts then I might be onto something. Otherwise, I'm looking at an extremely well-machined part construction.
Mrs Y and I are going to York for a weekend in the near future. If permitted (by Mrs Y) I'll pop in to the museum and see if I can glean some inspiration from there.
Thanks again.
Cheers,
Mick