I posted a homemade (not by me) album page here in 2010 that said these were printed in Udine in 1918, but that information was corrected in that thread to 1923.
So, somewhere in that time span of 1921 to 1923
Then, they were forged.
And yes, the forgeries can be distinguished from the fantasies.
ETA: Billig Vol. 30 (the Williams revision of Melville) says that pictures were printed in the 25 Feb 1923 issue an Italian newspaper, Domenica del Corriere
, and a printing firm in Udine immediately used those images to fabricate the set. The images aren't actually from Azerbaijan.
The frames from a 1919 issue were co-opted for the project, and the 500 and 25,000 ruble stamps don't have values in Turkish characters, because the printers didn't have anything to work from in those denominations out of the 1919 issue.