Excellent, just what I like with my breakfast coffee. Hard to date, could have been made almost any time in the 20th Century because Stuart have been going for donkeys years. Ditto Meccano, who provided the chain and sprocket wheels.
May I suggest three minor improvements, replacing parts out of character with the rest. Nothing difficult, and they offend my eye!

The switch at arrow ‘A’ is clearly designed for human fingers, and its scale is wrong for the model. And the d*mn thing being bright and shiny catches the eye. Nothing that size and shape existed in an engine house! Could be hidden round the back or replaced with a simple home-made brass knife switch scaled to match the man.
The plastic twin cable connected to the dynamo is also a bit out of place, though only a pendant might notice! First, wiring is never run at anything other than a right-angle, so drop it straight down to a new hole in the floor. Second, plastic insulated wire could be replaced with shiny brass strip or thick copper wire. Both look more like the open busbars found in early electrical installations, and would match the look of the steam installation.
The way the dynamo is fixed to the floor looks odd to me. No Aluminium in early engine rooms! The sticky out feet are unnecessary and the mounting seems over-complicated. Might be a poor implementation – an old dynamo I saw in Wales had a similar arrangement, except it the slim Aluminium in the model was replaced by a hefty balk of timber, a good way of reducing vibration on the cheap. I’d be happier if the model dynamo were bolted straight to the floor, or the Aluminium was disappeared by painting it black!
Sorry to be a fuss-pot, but minor anachronisms stand out in a first-class job!
OMG, I’ve turned into Inspector Meticulous. Nurse, where’s my medication…
🙂
Dave
And you wonder why model engineering (and this site) is failing to attract new blood. Prime example right here of the type of armchair nitpicking and negativity that has not only discouraged newcomers but also driven away many of the old hands.