Thanks for checking that for me. It is possible it was an AT-11 but I am not sure.
It will try to find his logbooks but it will take a while. After he passed away my aunt put all his stuff inside boxes and she told me it will be difficult to find.
I do have his medal and a diploma that came with the medal that say "pelo transporte de armamentos e pessoal".
I remember when I was a kid he mention something about Fernando de Noronha but again it was long time ago and I can be wrong.
Take care
Junker