Worn out

A pretty long and tiring day. Not helped by my after work swim being messed up by a pair of young women who swam very slowly in a convoy in my lane and causing everyone to slow down to their snails pace.

Just before giving up for the day I saw the article in the news about the new £1 that the Royal Mint is planning, so here is a blip of randomly selected old and very badly worn £1 from 1991. On closer inspection the coin is in poor condition and it could be a dud, but the milling on the edge is still pretty good which is usually a dead give away for a bad coin.

However, I can confirm that is a counterfeit? Brownie points for knowing why?