Interlocking Puzzle Piece Flat

I wanted to create a printable part that could take the place of the plywood that makes up the CupCakeCNC. I chose to make a repeating pattern of interlocking puzzle pieces. However, a single layer of these puzzle pieces would not be strong enough for anything but a toy. I added a set of holes that would allow offset layers of puzzle pieces to be bolted together, forming a stronger whole.

I expect to be starting into making corner and edge pieces. I think it would be possible to laser cut