Guštanj (today Ravne na Koroškem) is known for its long history of steel production. The Earl of Thurn owned a large steel mill, which was very important in the post-war reconstruction of Yugoslavia. Due to the intensive operation of the steel plant right after the liberation in 1945, the post office in Guštanj was also quite busy. It is known that this small post office was without any postmarks, so they had to use provisional ones...
1945 Maribor provisional issue, company stationery sent from Guštanj (26. JUN. 1945) to Muta ob Dravi, franked with 6 pf, canceled with a provisional date canceller. Signed Ercegović.
