Funny you should post this. I was looking for something similar.

My problem with the Altoids tin is that I EDC it in my hip pocket. The aluminum is too flimsy and the tin is completely dented.

Yesterday, I bought an "Aluma Wallet" from Walmart. It is available online for about $5 each but I paid over twice that.

It is a flimy case with a lousy hinge. I replaced the hinge pins with longer pins (paper clip). The aluminum is thin but is backed with thick plastic. I cut out the centers of the plastic to allow the inside of the tin to be larger. The "rims" of the plastic were then epoxyed back onto the aluminum case.

The advertising is that the case is "water resistant" but I have my doubts. I will be testing the aluminum wallet to see how it handles my hip pocket.

Thanks.
Conway Yee