Two types of forgeries are known...
Type I forgery is quite primitive and should not present a challenge to collectors. The overprint is narrower, lacks precision and uses different lettering. The coat-of-arms element shows the version associated with the Independent State of Croatia with blank square to upper left instead of the Banovina of Croatia shield with darkened square. In my opinion this forgery can only confuse collectors who did not have the opportunity to see the genuine overprint.
Type II forgery is more accomplished. Basic dimensions are close to the original and the difference lies in lettering where individual letters are somewhat thinner and less cleanly struck. Letter 'M' in Međimurje is slightly inclined to lower left and the entire lower inscription is raised by some 0.6 mm. Overall even this forgery can be recognized without difficulty.
For a complete article order:
ACTA PHILATELICA NOVA 2018
Croatian philatelic almanac
Independent State of Croatia
Međimurje local issue 1941
Chapters:
Introduction
Catalogue Listing
Overprint
Coat - of - arms
First Overprinting Phase
Second Overprinting Phase
Third Overprinting Phase
Additional Overprinting
Overprinted Stationery Postcard
Determining Overprint Types, Subtypes and Variants
Overprint Forgeries
Overprint Errors
Postal Use of Overprinted Stamps
Forgeries of Postal Use
Valuation of the Issue
Conclusion
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