Bit of an update on this one - I got most of the main systems in, to the point where the engine would run off a jerry can, but couldn't seem to get it over the line. So last November it went to Paul Lumley down in Bridgewater, the idea being that he'd have it for a couple of months and move it all along a bit.
Then COVID.
So last week it came back, after a little longer than expected! Now it's a runner, all the wiring's been sorted, it moves under its own steam. Not quite ready for the road yet, but psychologically, a runner that needs to meet the regs is much easier to manage than a static exhibit that just looks like a vehicle.
Decided to cover it on my Dave Makes Stuff Youtube channel; there's an intro and overview here: