I designed, drew up the model and created a mockup of the wallet. The measurements are skewed to allow the tag inside the wallet (this was intentional so that it would add body and have my contact info). The template was designed on drawing paper, so it's pretty thin. I think I'll make the actual boxes out of bristol board or a similar card stock. The x's are all parts that should be cut out.
Box Template 6 4/8'' x 12''
With the template cut out and tabs made (this will need refining), I ended up using tape. Ultimately I'll use glue or another adhesive that won't show.
Box fully assembled.
I wanted the box to fit snug but still have some space in case the gifter wanted to have tissue paper to gussy it up a bit. The wallet can lay flatter but it naturally bulges out. The card insert gives it body and also contains my email address and website link.
Box with wallet and card insert.