Slow progress while each stage dries, but here is the current progress. Grass matting has been glued in patches to the hill. The parts between have received a couple of coats of a mix of fence paint, polyfilla, PVA and sand. This has also been used to blend-in the grass may patches.
This view is from behind rebel lines:
And here we look up the hill along the line of where the bread twirl will go: