XF - may be NH. This is a Block of 12, not 6. 1863-1864 CSA Davis 10 cent stamp block 6 Archer Banknote Engravers No. 1" is in sale since Thursday, March 19, 2020. This item is in the category "Stamps\United States\Confederate States".
The seller is "tnstampman" and is located in Chattanooga, Tennessee. This item can be shipped to United States.