Thanks for the pictures. The brackets go on the inside, it looks like from the first picture? So the screws go from the outside, through the panel and into the bracket?
(wanders off to find someone to bend some brackets for her)
Put your favorite posters’ names on each of the sides, and call it a Dope-decahedron! 
Sell it to some Vegas bar, for them to paint them like dice and put them up as a prop ?
Sell them to some club of math-enthusiasts?
Dismantle them and donate the plywood to some place that offers underprivileged children the opportunitiy to do arts and crafts?