COINS, CHANNEL ISLANDS, GUERNSEY George VI (1936-1952), Cupro-nickel 8-Doubles, 1945H, central hole (Pr -; S -; KM -). Uncirculated and very rare, unrecorded in both Pridmore and Krause.
ex A L T McCammon collection, Baldwin's Auction 20, 11 October 1999, lot 160
There would be no reason whatsoever to ever think of this as a circulating coin and it is not a planchet taken from the BWA Penny bin, so it is not an 'error' as such. One possibility is that the metal, cupro-nickel, was considered for the Guernsey coins, and when that thought went no further than to strike this one coin. The mint holed it to make sure it didn't go into circulation.
Estimate: £300-400