Family Business
On the deathbed of Robert Anglin, one of their brothers, he admitted to being in touch with his two brothers between 1963 and 1987. He did say that he lost contact with them, but that they would communicate.
Not Worth The Chase
To this day, Interpol still calls this case an open investigation. If the Anglin siblings were to search for their brothers in Brazil, they could easily be arrested by Brazilian authorities.