"MIG" wrote

Do you happen to know the provenance of a 1970 two-shilling (ie 10p
till 1992) coin I found in my change once?

Was there an equivalent "last non-decimal coins" set available that
included coins that weren't generally made and that someone
accidentally spent? (Given that they started using 10p coins for 2s
in 1968.)

Yes - I have a set of 1970 pre-decimal coins, containing halfpenny, penny,
threepence, sixpence, shilling (English and Scottish versions), two
shillings, and half crown. Some of these were not minted for general
circulation in that year.

Weren't the coins enormous? The two shillings is the same diameter as the
current £2 coin, while both the penny and the half-crown are larger.

Peter