Folding up the frame and fitting the wheel bushes. I found the bushes to be a tight fit for the outside wheels and therefore easy to solder in place so that they didn't provide any springing, but the middle holes in the chassis are larger and the bushes merely fell through. I therefore used some bigger flange types I had left over from another model and together with a small strip enabled them to slide up and down the slots. Finally springing them with wire inside the frames completed the wheel fixings. Click for a larger image.
The brake gearing supplied was a bit of a mystery and I ended making up what I thought would be a passable solution, especially as after painting black and hidden from view it would not be too important.
Finally, the brake hangers were put together and the brake shoes glued into place as shown here.