The layout now has a cover panel below the front. This is cut from two pieces of 2mm MDF rescued from the back of an old bookcase, fixed on with No.6 self-tapping screws.
The large cut-out at the far end is for the wiring connector, this is a 7-way pluggable "chocolate block".
The panel gives some protection to the wiring buses, and it neatens up the overhang at the front, but I think in the main it says "I've finished underneath the layout for a while". No.4 screws would have been enough, but I couldn't find any locally.
The panel also adds about half a kilo to the weight of the whole layout, which has done nothing for my weight budget of "1kg per square foot", but I think it is worth doing, especially for when the time comes to transport the layout.