I've built one like that in your link bear 57.
I made one mod that has worked out way good. Instead of drilling holes in plywood just use a partial sheet of peg board. It comes stock with 1/4" holes on a 1" center grid. I put down a piece of packing tape in the middle of the board and draw a straight line down the middle. Mark the centers of all the formers and line em up with the line.