After completing the baseboard, I sealed up the MDF with diluted glue about 90% glue 10% water, I would advise this as MDF is very absorbant. I then glued the track plan down and using it cut the track to size. For this a pair of heavy duty wire cutters and a metal file were used. It is much cheaper than a xuron track cutter or dremel multi tool, it took longer but got the same result. After that the track was put together and the edges of some sleepers were cut to make then fit. Before laying the track, I applied a coat of grey paint, over which I will ballast eventually. It just stops any annoying white patches showing through.
Next up, Track laying and wiring.