Thank you Bruno; Obrigado Wayne
.
I have been trying in vain to contact Brazilian resources connected to their Navy, in order to decode that inscription; but it seems they are not that amenable. I would give my kingdom to know what those initials (?) mean.
If this were a later piece, EG could well mean Escola de Guerra, as they now call their Navy schools. But i can't get a trace to their Empire period Navy institutions.