Ok, so I cannot pretend this is secret anymore.
I have finally finished the surround and support for this board which is amde from 12mm MDF and battening crisscrossed beneath - I'll provide pictures of the woodwork when I have someone to take the pictures while I tip the board. In my normal manner this may be overkill, but I KNOW that I'll be able to transport the board without damaging it. On the other hand I am beginning to wonder just how strong the average war games exhibition table is?
Once the structure was complete I was able to put the board itself in, and then fill any of the gaps using - foam gap filler, (does exactly what it says on the can). You'll see that the MDF surround is cut to exactly match the contours of the edge of the board, providing very robust protection all around, and I hope a professional finish.
Having then cut off the extra gap filling foam I have been able to apply the plaster filler which will smooth all the surfaces together.
In the next picture you are looking from the smooth rolling tundra end of the board towards the fortified end.
The exposed yellow bits you can see are the foam insulation showing through where they will form cliffs, the grey areas are where I have smoothed out plaster to make rolling hills. You can just make out the smoothed road leading the length of the board and the right hand junction about half way down.
Due to the cold weather and the fact I am having to work in the garage, the glues and plaster are taking a very long time to set. So I am not going to touch this again until next weekend.
Next time - sanding, sanding, more sanding and probably a final plaster layer... and then yet more sanding.