there is still a lot of very old kit in S America - Paraguay is probably the worst
the Navy has 4 River defence vessels that are minesweeper /corvette size.
Captain Cabral commisioned 1908 - yes 109 years old "still in excellent condition"
Paraguay commisioned 1931
Teniente Farina commissioned July 1939
Itiapu commisioned 1985
The Army still runs Shermans & Stewart tanks from 1945
The Airforce is the most modern with a small force of Tucanos