I was trying to keep the number of variables down for making this happen and also trying keep the cost as low as possible. Plus I figured everyone would be creative on how to store them! I keep mine in an old bluetooth grill thermometer box LOL. I think the key ring is a great idea and should be pretty easy to do.
I considered adding tuck boxes on as a surprise for everyone using extra funds, but then the international shipping started looking like a big bogey on these and most of the generous "keep the change" offers came AFTER I placed the order. Sorry about that!
It's possible to order tuck boxes from makeplayingcards about $1 each plus shipping if someone wants to look into it. They have a bunch of other types of boxes as well.
https://www.makeplayingcards.com/design/tuckbox-large-playing-cards.html