I built a rackmount case to house the backplane for Small Computer Central.
It’s based on a 5″ lab rack server.
https://the-diy-life.com/i-built-a-5-portable-raspberry-pi-homelab/
It fits the SC112 (6-slot modular backplane) perfectly.
With CF cards installed, it fits neatly into a 5U case, but if you’re only using standard-sized cards, it looks like a 4U case would work as well.
I’m also planning to add a control panel.
If anyone is interested, I'm happy to share the 3D data for the tray.
-Yoshi