1941 MEĐIMURJE, unique letter

It is well known that Međimurje stamps were not sold at the post offices. However, the post office in Varaždin accepted and tolerated the use of these stamps. We know for about 20 letters that actually traveled and all of them were sent by Dr. Wolf from the Varaždin post office to different addresses in Zagreb.

Recently I got a letter that is unique from several perspectives:

• it is not the Dr. Wolf's law office envelope 
• it contains 0.25 Din stamps
• it contains stamps with both types of coat-of-arms
• it contains stamp with the typical error "Hrvatska država"
• and the most important, it was properly franked with 2 din for internal usage

1941 Međimurje, unofficial local provisional issue, properly franked with 2 din for internal usage, Varaždin (18.IV.1941). Certificate Vilfan.

Typical error "Hrvatska država" in horizontal pair with normal stamp (positions 2,3).