Thanks guys for the comments! Yes the figures came from the kit, and they are shiny, very much to my dismay, I put on three coats of Humbrol flat, and they still came up with a sheen, I think it was an old bottle that had separated. I may go back again, and try to add some of the Vallejo flat and see how that works.
As I said this was an experiment with the blue foamboard, the board is two inches thick stock, I ran a piece through the tablesaw, and then marked out two 45 degree angles, and used my compound mitre saw to cut th angles. This stuff is easy to cut with the saws, you get a fairly smooth cut, and if you want can sand it smoother with sand paper. I did this, and then I cut the upper barriers out of the foam, and glued them in place with white glue. Then I used Creamcoat Quaker Grey acryllic paint and brushed on three coats. I then hit it with a straight black artist oil wash, and as soon as I added the wash, the effect was perfect, it gave that rough concrete appearence. Then I just added some drybrushing and pastels to finish it off. Oh, and before painting, I took a knife and gouged out some holes here and there for a more of a broken effect.