Out came the sketch pad yet again. There had to be a way to eliminate one of the unique board types. These days we aren't overly restricted regarding the shape of a circuit board, so what if I played with the shape a bit?
What if the base board was combined with the verticals? I found that I could make a sea of holes at one end to accommodate mounting the controller board of choice. On the other end I could have an oddly shaped board with a long vertical run that had fingers coming out of each side. The LED boards could then mount onto the fingers as shown, and the controller board could mount at the other end. I was back to two unique circuit board types.
This method had the added benefit of cutting the number of 2mm 2x2 headers in half -- I would only need 64 of them now for a cost of $9.30. This is 75% less cost compared to the original sketch with all those 0.1” headers.
I was very happy with that cost number and figured the base board idea could be mounted vertically with the LEDs pointing outward, or it could be mounted flat with the LEDs pointing upward. Two different construction styles possible with one simple circuit board.