Came across a pile of these Portugese Military Aerogrammes. Here are a few that may interest the group...
#1 postmarked 1967 from Lisboa PO

#2 Postmarked in 1961 from Mocambique to Lisbon

#3 Postmarked in 1961 from Postugese Guinea to Lisbon

#4. Another from Portugese Guinea to RAC2 in Portugal. Postmarked 1962

#5. Postmarked from Angola to Lisbon. 1963

6. Finally, Postmarked from "EPM 6" which was Angola to Mozambique. 1963

Interesting items. I do not have a catalog on these, but one is available on special order from the author via the internet.
I can only assume that the green cards were the earlier versions, and they transformed into yellow ones as the time went on, or not.
These cards (from what I can determine) were in existance from 1961 to 1971 and were used at Portugese military installations around the world.
If any of you have any more information let me know, as there are a bunch of different "types" on these aerogrammes.
If anyone knows of a list that defines the camp numbers please let me know.
Enjoy.