I went to Lowes today & bought 3 – 2×4’s & 1 sheet of 4×8′ Smooth Brown Hardboard Wall Panel. The panel board was less than $8. I had lowes cut the panel board into 2′ widths. They are probably not all quite 2′ wide. I cut the 2×4’s into 8 – 2′ lenghths & also cut 4 1×2’s the bottom panel stops. I then cut a 3/4″ deep slot for the hardboard to slide in. I also cut an 1/8″ deep slot in the 1×2’s. I clamped all the 2×4’s onto the table using a 2′ long spacer for each of them so they are all the same height. I then checked the dimensions before finally cutting the hardboard to the proper widths. I just have screw all the 2×4’s in place now. Here is photo of the test fit with 2×4’s clamped in place.