Menai Bridge 1 pound coin dated 2004 discovered

[eurocoin]

A 2004-dated 1 pound coin depicting the Menai Bridge on its reverse was discovered in a still sealed Phila-Numismatic Cover (PNC). This coin was officially first introduced in 2005. It is unknown if other PNC's too contain a 2004-dated coin.

It may be a trial strike or a mule error in which mistakenly an old die was used.

[Alan71]

Interesting.  There was a pattern set of the 2004-07 designs in silver dated 2003, but these did not contain the denomination (in place of "One Pound" was "Pattern" I think).