tuatara said:Mid-19th century for sure. I've got exactly the same and did some research on it a long time ago. They supplied goods for colonies and were providers for Army and Navy. The buckle is military.

What is the rest of the mark? Is it a number?
It is probably CW Buckle. Go back and hunt for the center..
Great find!DG
Apparently SW Silver and CO also made Rifles for use during the Boer War period perhaps your buckle was a marksmanship badge ? i included a photo of the rifle and some information that be helpful Dd60