1950 FIFA World Cup Ticket Stub question

[danix75]

Hi everyone,
I’ve got a pale red color square shaped ticket stub from the 1950 FIFA World Cup in Brazil –a ticket for a five-person private box (“Camarote”)
Does anyone know how to tell real ones from fakes? Some say tickets with a rectangular ink stamp showing the countries are genuine, but I’ve heard fakes can have that too.
Mine is for the fourth round at Maracanã (Brazil vs Sweden). and only shows a CBD ink stamp. I know they supposedly stamped tickets when multiple matches were played on the same day at different stadiums. But as far as I know, only Maracanã had five-person boxes – Morumbi in São Paulo didn’t – so it seems odd to stamp tickets there ( if I´m not wrong ).
Can anyone clear this up? Thanks!
( I tried to upload the image of the ticket, but I couldn´t. If someone replies , please let me know how to upload the image so it shows on the page )