Question I have a Surrender of Lord Cornwallis at Yorktown sheet (Scott 1686) that is missing the USA on stamps "a" and "e" I am under the impression that they have some value. It has been very difficult to find any information on the internet.
Answer Not really my specialty. However, the 2010 Scott catalog assigns catalog # 1866g to the error sheet that you describe. Catalog valuation is $450.00. Dealer buy price will lower. A more accurate market value might be obtained by checking SOLD lots on eBay or asking prices from dealers who specialize in EFOs.
Almost any question relating to US postal stationery
Member UPSS 19th century catalog ediorial committee; member UPSS 20-21 century catalog editorial committee; member of APEX examiner committee; published author including regular column on US postal stationery in US Stamp News