royal life saving medal

Bought this sterling 1926 Birmingham silver life saving medal online. this were made by JA Wylie & Co. from London. I found similar(1909) but older medal on the internet with another makers mark JD & Co for Joseph Daffern & Co . Daffern were still making fob medals the same time this one were struck. How can they have the same design and why are this marked Birmingham in stead of London?

Jannie
Life saving medal front.jpg
Life saving medal back.jpg

Wylie’s mark was registered at Birmingham. They probably used a Birmingham company to make their medals and have them assayed locally. It was probably cheaper than going back to Dafferns. The medal design would have belonged to the Society rather than the manufacturer.

Thanks for the quick reply. I recently started to collect medals. Like the stories and history connected to them and the fact that they are mostly unique (unlike coins). They are also some of the smaller(and cheaper) items with full hallmarks on them.
Jannie