This is called “hell money”, or basically pseudo-money that was buried with the dead. The family members didn’t want to waste good money by burying it with their dead relative, so they created semblances of the coins in circulation out of clay or lead. Tiny, severely underweight issues are also considered funerary coins.
Do you suppose these were buried then "reclaimed", or just leftover samples? They look to be in pristine condition.
Thanks for looking a friend recently gave me a museum collection he bought around 30 years ago .Theres what they describe as Celtic ring money , Chinese shell money , Jade pieces .These Clay coins (I also have the coin moulds ) have been in a drawer for all that time.