Brazilian vehichles are weird, the year listed very well could be correct. Remember, they had old style volkswagen beatles up until the 90's. They would also buy obsolete stamping dies from Ford and make their own vehicles. Example: The 1986 Ford F1000... used 67-72 sheetmetal but they couldn't get the dies for the correct grill so they made a platic version to fit the space.
Truck is in nice shape surprised there's no rust considering how damp the country is. Do you know Marcelo who restores Simcas?