This design revision is a pretty major one! It is the first major redesign in about a year, and was in response to the brittle acrylic shipped with the initial Kickstarter orders. To be clear, it isn't that the acrylic itself is bad, but rather doesn't fit the design scheme involving small hooks and snaps.
You can download the Corel Draw laser cutting files, as well as the EPS export for both standard laser cutters and using the Ponoko online service here: Choosatron Case Laser Plans - Rev 18
We also fixed the tolerance issue around the power input hole (it was too tight), and added more cuttable bits around the optional power switch hole.
If you wish to add a power switch to your Choosatron, take a look at the Adding a Power Switch guide.
An annealing process (reheating the acrylic after cut) would likely strengthen the acrylic enough as to match the acrylic we were originally working with, where the hooks and snaps worked quite well.
In any case, this design is to remove all need for small, thin parts when it comes to structural integrity. The case is secured by four bars, each with two tabs that fall into place (essentially four gravity locks).
We didn't want the design to restrict you from open the case back up, as this is a kit to be modded and changed.
Here are a few better look at the full case.
Link to the plans again: Choosatron Case Laser Plans - Rev 18