Tail Tag Seals, Image by StuE, Found by Blue_yeti.
Found in South East England.
Rivet disc parts of two separate seals showing letters and numbers.
The rivet on the right hand seal displays a portion of the crowned Dutch shield bearing the rampant lion of Holland.
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.