I was watching a video of the completed train, within it they mentioned a flywheel. While trying to find the page for today’s build, I happen to notice the flywheel instructions. It was then I discovered I had skipped a page. So that was today’s build.
I also sneaked in an extra page, where the wheels finally connect to the main body. It took a while to work out that the frame sitting on top of the wheels was just a support during the wheel building process, allow the wheel assembly to rest on the table. If only I had realised that when I made the wheels!