Here are the dimensions. The box is 5" deep and 7 1/2" wide. The height depends on how many disks you have. The length of the slots is 6". The width of the slots for the flat disks is 1/4". The width of the slots for the conical disks is 7/8". The angle is about 45 degrees but is not critical. The only somewhat critical dimension is the distance between the slots. In my case the distance is 3" which gives about 1/2" between the hub on one disk and the plate on the next.
It is made from plain big box store 3/4" plywood that I had. I really wouldn't change anything. It works perfectly. Just make it out of what you have. 1/2" plywood would be more than adequate if that is what you have or you need to go buy the stock.