The most difficult challenge in designing these parts is the z-axis, or how everything sandwiches together. This was achieved after careful designing and tweaking.
The most important components in the assembly are: M2 x 4mm screws, and 0.05" pin headers. The pin headers are used to connect the button and ALS PCBs to the logic board, and the total stacked height must be 0.25" to work.
The files are viewable and downloadable on thingiverse:
Have fun, and if you 3D print them, let me know how it goes!