Motivated by @madvillain remix of my design, I decided to make numerous improvements to get the design to be very similar size of the original.

In the end the new design is 0.7mm wider and 2mm longer! However, the design will need a printer that has pretty good precision due to the reduction in tolerances in order to achieve the slim design. If your printer has a tendency to overshoot/over-extrude, some cleanup with a file may be required.

The new lever looks weird but it is very deliberate.

The push rod needs to be rotated in, this way there is no glue required.and the button is really secure. See the attached pictures on how to install. A piece of felt is required to prevent the cards from falling out, there is a slot provided for this purpose on the left side of the wallet. I found the best material to use is 3M sticky velcro and using only the fuzzy side (not the hook side).

The optional screw is M3x6(ish) or M2.5x6(ish). The money sheath is included from my previous design for convenience. Scaling the design in the Z direction will allow for more cards but only recommended that only one card be added as the walls increase in height as well.

Enjoy and post pictures of your prints!

EDIT: Added a cover with no screw hole and pushrod updated for smoother action, old pushrod renamed