I also had a deck of the Wonderland Tarot, which I used in a similar way. I decided I wanted to make a box to hold both decks, and this was the result.
It's made from standard balsa wood pieces from the hobby shop. Sides, top, and bottom were cut from 1/4" planks, with a smaller piece glued to the lid to provide a tight fit. Larger blocks were used in the bottom to make the recess for the tarot deck.
I used some scraps of suede to make a full-length hinge and a couple of strap closures which fit over the heads of two brass wood screws.
The whole thing was put together with wood glue, sanded smooth, decorated with a woodburning tool using images from the cards, and then finished with linseed oil.