Reverse image searched the Visual Dictionary photo, and came across a few good leads.
It looks a lot like some sort of compression valve, though I’ve been unable to find the exact shape. The medallion seems to have 5 overlapping ring cutouts around the rim, while every compressor valve I’ve seen always has 3 or 6.
Which leads to another possible source:
Valves and nozzles for “interactive fountains,” those ones that hook up to LED and sync up with music. These too look promising in terms of shaping and size, but still no positive ID yet.
Yet another option is a variant of a ceiling light mounting bracket, but they all appear to have screw holes and an incorrect ring layout:
I hope this bit of digging helps in the search, if it is indeed a found object. If anything, maybe someone will make a 3D model that can be printed in metal, honestly surprised it hasn’t happened already considering it’s a rather small and simple design.