Lion Seal, Image & Found by Puffin.
Found South Staffordshire.
One side has a shield with a rearing lion or other animal rearing up to what could be a raised arm. The other side has the letter G at the top possibly with other letters either side [from Puffin, "The letters look like ICC or IGG"] and below is the number 187 or 18 followed by the letter Y. There also appers to be a smaller letter H? before the number.
Has the look of a customs seal.
See PAS LON-8FDA34 "Lead-alloy seal for attachment to a cow's ear. One side has illegible lettering and possibly '78'; other side has a rampant animal with staff/sword all below crown. These seals attached to the ears of live animals imported from the Netherlands from c. 1814 on, probably into the 20th century (Geoff Egan, pers comm)."
From Jan van Oostveen, "It was only used for the tail and not for the ear. ... from authentic documentation from the mid-19th century where it is mentioned how these seals were used. [Scheffer, D.H., 1909. De Geslachtswet. Amsterdam.]" See Oostveen, J. van, 2019, Tax seals used in The Netherlands as proof that 'accijns op het geslacht' was paid.