Here's the order of assembly:

1. Place the on/off switch into its spot in the case bottom
2. Set the battery on the case bottom
3. Push the antenna cable through the hole at the top of the case, allowing the lower nut to be held captive, then put the washer and other nut onto the outside and screw into place
4. Fit the rotary encoder in place and screw down the washer and nut from the outside, then screw on the knob, leaving enough space to click the encoder shaft
5. Slide the Trellis mount into its place in the mid case
6. Slide the Feather mount into place as well
7. Screw the Feather onto its mount using three 2.5mm nylon screws and nuts, then place the OLED FeatherWing onto the Feather.

8. Push the Trellis into its mount

9. Set the silicone keypad into place, making sure to get the orientation correct by aligning the keyed rubber protrusions to their equivalent holes in the PCB
10. Place the lid on top
11. Screw the two top screws (1-1/4" long) into the case from the top, making sure they thread through all tabs, leave them about 1/2" unthreaded so you can add the case bottom later
12. Next, screw in the middle two screws (1-1/8" long) from the top
13. Screw in the bottom two screws (1-1/4") from the top
14. Use double-stick tape or a piece of foam to prevent the battery from rattling around, then press the case bottom into place
15. Screw all six screws the rest of the way down
16. Thread the antenna into place