Model R66 Heat Regulator

I"ve recently insatlled a DS Machine 1500. My brother gave my what appears to be a barometric (or some sort of) damper.
My problems are three fold (1) there are no instructions for the safe operations of the device, (2) although there is no
manual type damper in the device; it seems (as there are holes on either side of the pipe to accomodate the handle) there
should be. Yet everything I've read tells me that a manual damper should be at leate 18" below a barometric damper. And (3)
I can find nothing about the device or the company that made it--It is Heatrite Model R66, manufactured by Heatrite
Regulator Co. Of Phila Pa.
Before I do something stupid, can someone out there educate about this device or should I just junk it?

Can you post a picture of said device?

I'm betting it's a heat reclaimer that goes in the flue pipe...

Thank you very much for the comeback. I loaned my camera out and as soon as I get it back
I will submit the photos of the device.
Again, thank you very much.

As promised here are the photos of the device. Hope they will help. The door is opened by a cam behind turned by the
regulator adjustment knob. Again there appears to be a place to put a manual damper at the bottom of the pipe. There
are no tubes or weights behind the door.

WOW. Looks like some type of old Auomated/Baro damper regulator with adjustment knob to regulate the opening and pull more or less air from the room (more heat in the stove) etc.. maybe it has a heat coil spring so it automatically regulates based on temps?