More Info on These Wagons?

.....but may be a bit tall for passing through any 3" risers.

I've been re-visiting some of his other videos. Several extended funnels on view, so he probably doesn't do standard height bridge supports.

I like the way he's had a tame mole dig a cutting across his grass. I'm pretty sure that looooong train is running downhill.

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He made the Hoppers himself they are customs looks like he took the tops of model train hoppers and affixed them to Tomy wheel beds

Nice revolving image here:
Hornby Bulk Grain Hopper Wagon