I've been informed by Paul Withers that this is an unlisted mule that was previously unreported,& that it was struck by an unscrupulous coiner named Henry Morgan in London.
Henry Morgan was the early 19th. Century equivilant of W.J. Taylor,who was an unscrupulous coiner in the late 1830's & 1840's.
I bought this coin off a late friend of mine in 2000 for a bargain price - NZ$2!