American Postal Machine Company, Washington, D.C., May 24, 1897. Type B-27 slogan flag cancel "Congres Postal Universel" on uprated 1¢ Jefferson postal card to Germany, with Hamburg rec'd marking, fed through the cancelling machine vertically to mark stamp, Very Fine. Estimate  $200 - 300. $0 (Image)

American Postal Machine Company, Washington, D.C., May 25, 1897. Type B-27 flag cancel "Congres Postal Universel" with matching corner card on cover to Germany, German rec'd marking on back; faint vertical crease down middle of cover and partial backflap, otherwise Very Fine. Estimate  $200 - 300. $0 (Image)

American Postal Machine Company, Washington, D.C., May 29, 1897. Type B-27 flag cancel "Congres Postal Universel" on locally addressed pioneer picture 1¢ Jefferson postal card with picture of Army and Navy Building in Washington D.C. on back of card, Very Fine and choice. Estimate  $200 - 300. $0 (Image)

American Postal Machine Company, Washington, D.C., May 26, 1897. Bold Type B-27 flag cancel "Congres Postal Universel" on cover to N.Y. with appropriate transit markings on back, Very Fine, nice clean commercial use. Estimate  $150 - 200. $0 (Image)

American Postal Machine Company, Washington, D.C., May 26, 1897. Type B-27 flag cancel "Congres Postal Universel" with matching corner card on cover to Fremont, Neb., nice clean usage with Fremont rec'd marking on back, Very Fine and choice. Estimate  $150 - 200. $0 (Image)

American Postal Machine Company, Washington, D.C., May 24. 1897. Type B-27 flag cancel "Congres Postal Universel" on 1¢ Jefferson postal card with Brooklyn rec'd marking, Very Fine. Estimate  $100 - 150. $0 (Image)