The next stage was adding the tracks. These have been numbered on the sprues and this is the order around the wheels that they go.
The largest pieces of track I had were quite warped, but immersing them in hot water allowed me to get them nice and flat. The key I found in placing the track was to get the largest piece flat attached to the rear cog.
I managed to get the right side track to fit. It was quite a struggle to get the bits underneath the rear flatbed in, but it all came together in the end.
And now the left…
The workbench feature on the Big Trakk may help anyone else putting one of these kits together.