This is: a pair of reprint blocks of the Confederate States of America's 2-cent stamp featuring John C. Calhoun. The 2 blocks of 4 are in brown and orange. These stamps may have been printed using the original Confederate dies, stored in England (where the Confederates had their stamps printed) after the Civil War. Reprints like these have been made since the 1960s.
These blocks of 4 are on flat paper with no gum, as originally printed.
Check the scans for details.