Got this wrapped up (for now) today.
Battery holder secured here. This guy was a lucky find in my parts box. I had one of those regular clippy ones without the base for this and after I’d secured it to the panel I found this one.
Front panel screwed in and secured.
The prologue is that I still haven’t found a back I like. The board is just kind of hanging out inside the case, which i think is OK for a long time. There are a lot of wires and it’s very sturdy. In fact, getting it to move may be the hardest part of installing the back. I’m sure I’ll come across some scrap paneling at some point and get the back of my dreams.
I highly recommend this project for ease of assembly and awesomeness of sound.