This issue was made by the large company S.H. Gutmann from Belišće, which had a large quantity of old Yugoslavian stamps in their depot already with perfins S.H.G. When the new state was proclaimed, they made a new overprint in violet color N.D.H. and continued using those stamps on their letters.
After all old Yugoslavian stamps were used, this company started to use NDH stamps with perfins S.H.G.
