George McCaul was born in Perthshire, Scotland, in 1835. He completed his apprenticeship as a plumber there, before moving on to Birmingham and then to London. When the gold rushes began in Australia he travelled to Adelaide and then to the gold fields.
He tried his luck again in the early 1860s when gold was discovered in New Zealand, sailing on the Red Jacket to a field known as Gabriel's Gully, near Lawrence in Otago province. He moved on to the Hokitika fields when gold was discovered there. To get there, he and many others had to cross New Zealand's South Island from east to west, and cover more than half the island's length in their journey. Many men died during the journey. McCaul did not have any luck at the Hokitika fields either, but H.A. Robinson records that he remembered 'two ton of the precious stuff taken out of the famous Caledonia (mine) in a week.' (Robinson, 1974)
After abandoning gold prospecting McCaul moved to Grahamstown in Thames, in the north of the North Island, where he returned to his trade. He issued a trade token penny there in 1874, and is said to have put it into circulation by paying his men in it. After retiring from his business he moved to Auckland and died there in 1932 at the age of 96.
Robinson, H.A.. 'Auckland Tradesmen's Tokens.' The New Zealand Numismatic Journal. May 1974. p. 141.