Further work over the last week and I'm now up to 6 boards.
The last 2 boards in the current batch are behind for a variety of reasons. First up I could not find the rare earth magnets in their last location. After turning that area of the garage over twice, they were located hanging of my bike brake cable. Next I drilled the holes for the magnets, carefully arranged the orientations so that they matched the previously made boards. Failed on this point and have had to re glue 1/2 the magnets in.
I managed to pick up some Coir mats cheap and I've been knocking out more forests.
I think I'm still on target....