Napoleon and Britannia coins fused together

I came across a strange one while digging through my grandpa's collection.



It is two coins fused together:

• 5 Centimes, Napoleon III, France, 1864
  

• 1/2 Penny, Queen Victoria, UK, unknown date
  

It seems the fusing was done in a mold, as the excess copper of the larger 1/2 penny has spread to encase the French coin. So I am wondering if this a known practice and that this is therefore some kind of token, or if it is just the product of someone playing around with their new hydraulic press.

Thanks for any insights!

Something a bit similar has been post on the french forum today : https://fr.numista.com/forum/topic65575.html#p530539