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19th Century US Stamped Envelope Catalog Corrections:

• Identifying 19th Century Dies
• Identifying 19th Century Knives

• Errata for 20th/21st Century Printed Catalog 4th Edition
• New Listings (Apr 5, 2021)
• Knives and logos

• Identifying 20th & 21st Century Dies
• Identifying 20th and 21st Century Knives
• Identifying 1904 Recut Dies
• 1904 recut pricing (revised 18 May 2011)
• 2004 catalog entries that could not be verified
• Promotional sample envelopes of the 20th century
• U617 varieties
• Double impressions
• Corner cards on revalued envelopes (revised 31 May 2012)

• Corrections to the Envelope Specimen Catalog (2 February 2014)

Postal Stationery of Mexico Errata (August 2018)