The Turks & Caicos island coins are official coins; they were legal tender - the Turks & Caicos crown was set at par with the dollar, and I have seen some very heavily circulated examples of the quarter-crown.
To qualify as an "unofficial" coinage, it has to be listed in the "Unusual world coins" book, and therefore have an "X" number in the NGC
world coin database. The entry for the Lundy 1 puffin
shows it to be unofficial (the reference number is X# Tn2). These coins were once listed in the mainstream Krause catalogues, but moved to UWC because they logically belong there (having officially and legally been declared invalid coinage in a British court of law). The entry for the Turks & Caicos crown
lists it as "KM# 1" - an official coin, the first for the islands.
Krause isn't infallible - for example, they still list some Nauru coinage as "official", even though Nauru has never issued any official coins - but they get it right most of the time and it can be assumed to be correct until proven otherwise.
Now, for my own contributions to the topic. I'm away from my collection and my main computer right now, but here's a couple that
I downloaded earlier.
Hutt River Province "5 dollars" 1991. This coin is doubly-unofficial: it was made in the name of an unrecognized country (thus all HRP coins are in the UWC catalogue) and it was made without the authorization of the "legitimate" government of Hutt River Province. This is one of a gazillion pseudo-coins featuring "Desert Storm" military units, issued by a coin dealership in California and mass-marketed to Americans.
Behold, a coin from Middle Earth - the entirely fictitious world of JRR Tolkein and "Lord of the Rings". This purports to be a coin of the dwarf-kingdom of Moria. It reads, in Tolkein's dwarf-runes, "Balin, Lord of Moria". I also have a coin from the dwarf-kingdom of Erebor.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis