In response to John Kane's enquiry regarding the Polyphon 'medallion'
type label -- given the accuracy, consistency, and manufacturing
techniques used back in the day, the originals would have been machine
pressed in great numbers.

So it's unlikely to be one-half of a punch-and-die set...  But never
say 'never', especially without close scrutiny of the item.  However,
I have seen reproductions offered for sale on eBay that fairly
accurately fit John's description and images.

To help determine, it's worth noting the quality of the milled style
decoration around the periphery.  The original pressed brass item
tended to enjoy sharp definition.  My suggestion is, watch out for
one being listed and compare.

Hope this sheds a little light on the matter.

Mark Singleton, UK