More progress. So to speak.
I've re-ballasted the 6 foot. Not hugely successfully, but it doesn't look too awful unless I'm looking for flaws. Also painted the railsides with some Tamiya "flat brown", with quite a pleasing effect. I suspect it would have been easier to have done the painting before the ballasting, though, since it went on much more easily on the unballasted bit (where the grade crossing will ultimately be going).
That dent in the front track is from when I learned a valuable lesson about drilling the holes for wiring (I say that, but I'm not entirely sure how I'd avoid it happening again). It looks worse than it is, to be honest, everything runs over it fine, so I'll live with it. This project is more about learning than anything else.