I also have sold quite a few of these. Instead of penny drop, I was lazy and used coin drop.
The coin drop game pictured is 3/8” Baltic birch, 9x5x2 1/2. With a hinged lid.
The penny drop is a bandsaw box, made from alder. The dimensions are 7x3 3/4 x1 3/4.
it is a lot of fun to play.
I include two rolls of pennies, laminated directions and a $1.00 scratch off. I tell people that the pennies should stay with the game. (Who the heck carry’s pennies these days). The scratch off is used as an example of what you can use as a prize for the winner. Plus, it’s great marketing.