The Communists took over 1948, but as stationery goes the big change came 1954
with the introduction of the small Coat of arms with R.P.Romina (Romana) in a straight line
and with the introduction of lots and lots of pre-stamped envelopes

I work based on Michel Ganzsachen, which means I use their distinction of stationery
with Coat of Arms (CoA)
or with any other image (Other)

As the Coat of Arms go, there are many different types: Six types of Coat of arms images 

There are some german phrases that might be better translated than what I can do:
Other postcards:
Service: Dienst-postkarte
Other envelopes:
Recommended : Einschreibe-umschlage
Justice: Dienst-umschlage
Citatie: Dienst- faltbriefe

There are some cards & envelopes which I can´t identify - do help me if you know better!
If I´ve made mistakes, correct me.

This is slow work, and I doubt if it will ever reach 2009 (or 1970...), let´s see how far we can get :-)
Meanwhile - some of the pages are empty - have patience