I have some flat show cases 32x29 x3 , i have priced the 2x2 trats to hold coins, but the shipping is almost as high as the item. Iused my table saw and cut grooves in lumber , so the 2x2 willstand up, but it looks cheap, i am not very happy with the appearance.
I would experiment with types of hardwood and stains, maybe even a raw prefabricated molding if it wasn't too ornate. Also, entering in the groove at a slight angle might help. I'm sure something simple and nice can be handcrafted without too much effort or cost...
