Antique Binoculars - WWI era?

I have a set of antique binoculars I bought at an antique fair. The vendor said that they were WWI era British binoculars but I am not so sure and I wanted to check.

They are about the size of my hand and made of a heavier metal (brass?) with rubbed off black paint. There are a few dents in them but otherwise they are in good condition. The pieces on the larger side have a circular bit that slides off to reduce glare on the glass, similiar to how a telescope piece slides. 

I cannot for the life of me find a makers mark anywhere. No markings, just a few dents and wear. The only label I can find is on the top near the "nose piece" area between the lenses, which is a small plate label that just says "The Spy".

I honestly just want to know more about the item, and I am not concerned as much with what it is worth.

Fair