Hat Display Hanger Button Only

I had some difficulty pulling the side panels of my hats into the original design (https://www.thingiverse.com/thing:4486630) . When I had, I realized it was more work to take the hats out if I wanted to wear them. It took a couple of size adjustments and angles, but Button Rev 5 is the best fit for most hats. I did have 1 hat which required a tighter fit, unsure which revision that was, but it is in there as I included all revisions.
2 small nails fit perfectly into the holes and shouldn't push through. I also discovered the perfect spacing between hats was if I put a Hot Wheels card sideways on top of one hanger and had the bottom of the next hanger on the other side of the card.

I used nails similar to these.

https://homedepot.scene7.com/is/image/homedepotcanada/p_1000683600.jpg?op_sharpen=1