That "Army of the North" set was heavily forged, even though it is a very common stamp.
The pic you provided shows a forgery, not a genuine 10k stamp.
The original was printed on an off-white paper, sometimes appearing to have a bluish tint. The edges of both swords should be double-lines, not thick single lines. Also, the cross inside the wreath should be very well defined (especially the inside corners), not the poorly define slightly rounded corners.
Forgeries were printed on several paper types. Any 10k stamp printed on the buff/brownish paper is definitely a forgery. Ones printed on other paper types, you need to check the design differences mentioned in the preceding paragraph.
Still, a nice stamp to have. This is one set that is not too difficult to get a complete set of genuine AND a complete set of forgeries.
Thanks for posting the pic!

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