I agree with @fuzzy that the disc of metal looks added (due to the extra soldering or braze material that shows along the periphery. Seems like an odd item to make into a pin--wonder why it was done? 
"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz























