In 1884 Eustace had a small tin smithing business in Dunedin, manufacturing, among other things, lids for tins. Back then they were making slip-on lids, which are fine for many purposes, but are sadly lacking when it comes to any application where the contents of the tin need to be protected from the air, such as tins to hold foodstuffs. Eustace and his brother played around with a few ideas, and stuck upon the lid system we know today. Pleased with themselves, they started to manufacture the lids, and patented the idea. But here's the rub. They only patented it in New Zealand, and one of the quirks of the patent system is that you need to get a patent in each country you want protection from copy-cats.
To facilitate the manufacture of the lids, Eustace decided to get a 'die', or cut-out, made in England. The English were obviously very taken with Eustace's ideas, for not long after his dies were made and returned, the pair noticed that some of the paint they were getting from England had their lid design. They were legally unprotected, and could do nothing to stop a flood of companies in England from basically stealing their idea and making money from it.