I've done a bit more work on the scenic side. In its former OO state there was a small brick lined recess for the base of the water tower. This I have now filled in with card formers and a lattice work of thin card covered with thick kitchen towel soaked in PVA. I've just given it a thin coat of filler which I will seal with paint then cover with a ground cover material. The area was too small to do much else with really.
I want to make a wooden hut and loading platform in the space at the front when I can get some balsa wood, which I think is the best material for the job.
The tractor based device is loosely based on one made by Muir Hill although theirs used a Fordson Standard as the power source. Mine is powered by a Forson 27N which has the same engine as the Standard but is taller. It was given to me by an 009 modeller who thought I could use it in my scrap pile. It was much too good to do that with so I used to power the rail truck.
I reality the Fordson 27N had a three speed gearbox but could be fitted with a Darlington Overdrive gearbox which doubled the gears available. Presumably by changing the size of the sprockets on the final drive system could be made to give a higher top speed than the 7 mph you got with the standard three speed box.
The Tilly is used purely for maintenance work as it is too light to push loads of potatoes about, A small wagon with a few tolls is about all it can manage.