I while ago I bought this very nice kit
and assembled it.
I quickly realized that I'd like a box behind the PiDP, and it would have to be a heavy one so that I could handle the buttons without the machine toppling over.
Another reason for a box was that it'd allow me to tuck away cables and power supply more conveniently. E.g., got around the problem mentioned on https://obsolescence.wixsite.com/obsolescence/pidp-11-connectivity-options about the usb connector being too deep.
The main reason, however, was having a fun project to work on :)
Adding the cover:
And here are some weights in the back:
(just some steel strips) for that 'heavy' box.
And the back cover: