Quite an interesting DIY project!
Let me 'reverse guess' the thoughts that went into making this.
The main plate / flange has mounting holes .... so I suspect that it was originally made to mount on one of those electronic gear racks / cabinets. Mind you, finding a factory-made strip that mounts on the rack hasn't always been easy. Ordinary outlet strips are deliberately designed to make secure mounting difficult.
Then there's the orientation of the receptacles. With the number of things that have 'wall wart' transformers serving as plugs, it's hard to find a power strip that doesn't lose three spaces whenever you plug in one!
The variety of parts suggests that whoever made this scavenged parts, maybe even brought some from home.The coating of whit paint is an .... interesting .... touch.
