The AotC needed some 'period' models to run on it. Period being early 1980s in model terms. Here's one I did earlier in true Blue Peter fashion. It's an Aifix ( I think) body, probably out of a rummage box, mated with a Ratio chassis. The weathering is light. There is a trend to make things look decrepit these days. This is probably a bit of overkill in most cases as anything looking that rough would be taken off and repaired. This is just a bit grimy, though looking at this I note that the insides are a bit too clean.
The track is the obvious Peco code 100. This would have been almost the only choice at the time if you didn't want to built your own. The wire-in-tube control is just visible.