There is a pattern for every state. Use a 1 inch forstner bit to drill the hole for the quarter. Only drill to the depth of the quarter. Epoxy the quarter in place. The pen funnels and pens are optional. Use 1/2" thick wood for this project. Offset the quarter display to the back of the oval base if you plan to attach the pen funnels.
If you are going to attend any 4th of July festivals this might be a good seller.