Articulating, Wall-Mounted... Plate?

I took the case back that was made for a 7 inch display and absolutely butchered it in Tinkercad until it was just a plate with a reinforced knob at the back. That is to say, I used a big box and the group tool.

https://www.tinkercad.com/things/7PTTd9QDTs9

I needed a quick and dirty way to mount a tiny keyboard, and by jove did I do that thing.