Portugal Emigration and Immigration
From around 1836-1976 the Azores was split into three districts:
Angra do Heroismo: consisting of Terceira, Sao Jorge & Graciosa
Horta: consisting of Pico Faial, Flores & Corvo
Ponta Delgada: consisting of Sao Miguel & Santa Maria
It is my understanding that for this time period all passports on the Azores were issued through one of these three districts. The Government of the Azores has a digital collection consisting of passports issued at Ponta Delgada on this web site:
http://www.culturacores.azores.gov.pt/ig/passaportes/Default.aspx