I think I have taken on a rather large task. I am attempting to create some sort of order from the postal chaos that seems to have been happening in the Balkan area following WW II.
For now, I have two questions. The first one deal with some Croation Issues that have been overprinted by Jugoslavia. I cannot find these in Scott at all.
The two sets in question are posted below.

I have picked one to show the overprint. It seems standard to all the stamps except for the value.

Are these issues at all recognized and were they intended for use anywhere within the Jugoslav Federation or were they for a specific area?
The second question is about issues for Trieste. I believe this page shows issues for that region.

They are either printed with the region designation or are Jugoslav issues overprinted without obliterating the country name, Jugoslavia.
Examples of each are shown.


Again, were these intended for general use or for use only in Trieste? And can anyone give me a more accurate translation of the name "STT VUJNA" or "S.T.T. V.U.J.A." .
Thank you for any answers you may have.