The New Zealand penny should indeed be bronze; I'd say yours has been silvered. Given it's been holed as well, it's probably been turned into a medallion or keyring.
The Brazilian coin is a 400 reis from 1938; it's made of cupronickel and CV is 50¢ in Fine. The reis is the old, "predecimal" Brazilian denomination; Brazil has reformed their currency at least seven times since that coin was issued

, so it's hard to give a direct correlation between it and the US dollar, but to give some idea the highest denomination issued at the same time was a 5000 reis coin; it was .600 silver and about the size of a US half-dollar.
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