I took the reference design and moved the center line up 1/8". I also hacked a substantial portion of the par-metal frame to accommodate the various connectors. Finally, I snipped a small amount of the insulator washers on the RCA terminals just a tiny bit. Here's the result!

Another rookie mistake:
I also cleaned up some of the internal wiring in the power supply. In doing so, I made an error and hooked up the σ22's xfmr leads out of phase. Upon energization, the σ22 broke - Q1 is now verified broken. A replacement is on the way. Hopefully it's the only part that's broken. I went ahead and ordered a few of the BJTs and extra Zeners, just in case. I also got an orange display for my γ3 and some orange LEDs. I'll probably wait until final fitment to install it.
I also cleaned up the wiring on γ3. I have the XLR shields hooked up to IG now. I may in the future add a DPDT on-off-on switch that allows me to connect the shield to either IG, the chassis, or nothing at all. That's pretty deep down the rabbit hole, though. I'll probably just leave it alone. I fear I've read too much about Pin 1 and am suffering from information overload.

