Philadria d.o.o. - catalog 20th auction - October 2018
,34 (2), 36/7,Cover (few brown stains), franked with 50 para (2 K.), sent registered from Bled (3.II.21) to Zagreb (921 FEB 4). The cover is probably philatelically inspired. The addressee is Žiga Altstädter and the sender was probably Gaber. Rare use of 20 para value on cover !