Here's what the circuit looks like when directly wired to the Feather. Don't solder this together just yet, we'll use the Feather Tripler as shown below for the build.
This view shows the same wiring (minus the enable switch) but with the screen to the left of the Feather as it will be on the Tripler.
Here's an initial layout to determine parts placement on the FeatherWing Tripler.
This diagram shows the display wired to the Feather via the Tripler. This illustration has the display off to the side for clarity. On the real board you'll use the header to connect the display to the board with this wiring in place.
Here's what it looks like with the display in place but the wiring visible x-ray style.
Non-xray version. Note that the display will not overlap the Feather in the final board, thanks to an angled stacking header.
A compact way to attach the Feather to the board, while allowing the Joy FeatherWing to mount on top is to solder extra-long pins directly through the Feather to the Tripler as shown here.
Then, solder the socket headers to the Joy FeatherWing.
Screen Socket Soldering
Use a tall stacking header to create a pluggable socket for the display.
This will set the screen at a good height for the build, and you can bend the long headers to use as connection points for the wires on the FeatherWing Tripler.
Follow the wiring in the photo as well as the Fritzing diagrams above.
Solder in the slide switch as well and wire it to the ground and Enable pins of the Feather.
Use a length of double-stick foam tape to secure the battery to the FeatherWing. This will keep it from rattling around inside your Pip-Boy.
Assemble the Pip-Boy Components
Plug in the Joy FeatherWing, and the display.
It's now ready for coding and case assembly.