The main baseboard was constructed from some spare chipboard scraps which were recovered from a skip. The two cable drum bases were of different sizes and needed a fair bit of trimming and sanding before they were joined together with woodworking glue.
As you can see in the first image, I used a simple pieces of string and a pencil to mark-out the curved front edge.
The front was cut with a jigsaw and I used more scrap wood (pallet wood) to add supports to the under side which were both glued and nailed in place.
The final image shows the simple oval track plan being drawn on to the baseboard. The biggest disadvantage with the construction is that the 20mm thick chipboard is so heavy. I will have to do something about that.....