The NFL$ was actually Spanish colonial pesos/8 reales, but they had a different rate in the US and Canada. Canada just copied US developments, while NFL followed UK colonial policy. Before 1825, the NFL$ had a rate of 5 shillings. Afterwards, it was fixed at 4s 4d currency. The word currency is important. The currency pound was set at 17/4 sterling (UK money) or, a pound in coins was worth 1/3/1 currency. The rates were tinkered with further until in 1887 (50 Vict. cap. 4) the pound currency was deleted as intermediate reference.
The story is different for gold. Newfoundland adopted the gold standard in 1863, after Canada had done the same. It rated the NFL$ gold at 5 shillings, so 2 dollars gold was not the same as 2 dollars silver when expressed in sterling.
Source: A History of the Currency in the British Colonies by Robert Chalmers (London, 1893). There's much more detail in the book on NFL$ as well as the reforms of 1825, which were meant for all British colonies.
Peter