Who made this shutter? Geared Double Flap?

[Nick Ahlgrim]

I got this shutter and am having trouble figuring out who made it. Its a double flap pneumatic shutter with geared movement. Spent the past few hours searching online and still haven't got a match.

The only markings I can find is the word "patented" faintly printed on the cylinder.

Really want to know who made it.

Let me know if you have any idea

[Steven Tribe]

The double flap is a Guerry innovation, but this was made by someone else!
Are the flaps solid wood or wire frames covered with velvet?

[Nick Ahlgrim]

The flaps are made of a thin metal and they are painted black.

I still haven't found anything that looks similar.

[Nick Ahlgrim]

Found more writing on the shutter, looks like it says "SILTNIO."