Wonderful piece, Vladimir,
No surprise that models based on gears that you mention fascinate me since my model, ("An Artist's Modest Proposal") involves magnet gear trains and spatially repeated magnet matrices.
Regarding the question of "real" models, I came across a sentence in a skinny book for laymen by Feynman in which he disabuses his audience of imagining that atoms are in any way mechanically determined devices. He says, "There are no gears down there." I Googled and also found the following by Feynman: "...I can safely say that nobody understands quantum mechanics. So do not take the lecture too seriously, feeling that you really have to understand in terms of some model what I am going to describe, but just relax and enjoy it. I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that?' because you will get 'down the drain', into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that."
It is uncanny this long-held view that seems to be applied only to quantum physics - the restriction against physical models born of speculative reasoning. Imagine how limited the science of astronomy would be today if it had imposed on itself a similar restriction for the past 85 years.
Vladimir, you have written and painted a beautiful essay. Truth is beauty, and all that...
With admiration,
Ken