A VG unused example of the 2c black from the 1878-1880 Official Overprints Type 2 Luxembourg Printing. Without a certificate these overprints are difficult to expertize, as they have been fairly extensively forged. I have checked the basic stamp against the stamp forgeries website, and can confirm that the stamp is genuine. I have also attempted to determine the authenticuty of the overprint as explained in this week's blog post. Based on my findings, I do believe this to be a genuine overprint. It should be noted that as explained in Scott, the mint prices for these stamps are for examples without gum. There is a pulled perf at the bottom, which lowers the grade from fine to VG. Scott cat. $190 for VF. Our estimate of the value based on the condition is $45.
