GEORGE IV 1826 Halfpenny Roman I in date.

Origins from a 1 punch used accidentally upside down when the date was strengthened, there is a 1826 farthing equivalent which is not even close in rarity terms but is much rarer than the 1823 roman I in date.

The standard example above is quite possibly from the actual die which was to have its date strengthened later in time and become the Roman I type collectors today now look out for.

All in all i have just seen four example of this coin, this grade is about on par with the lesser of the other three specimens but the other two halfpennies were in a grade fine. Halfpenny grades good fair and is extremely rare probably excessively due to the lack of  ( sightings ) appearances.