Core identification and history references
- Typewriter Database — serial-number tables, galleries, model records, patents, and typeface examples. Individual table notes should be read carefully.
- Smithsonian National Museum of American History typewriter collections — object records and historical context for Underwood, Remington, Corona, Smith-Corona, and other machines.
- IBM history: The Selectric — official IBM history of the 1961 Selectric system and its market impact.
- Museum of Modern Art: Lettera 22 — collection record for Marcello Nizzoli’s 1950 Olivetti portable design.
Marketplace structure
- eBay Collectible Typewriters — active marketplace category used for focused shopping links.
- eBay Antique Typewriters — antique-category inventory and filters.
Editorial method
We use museum and manufacturer records for historical claims, serial tables and galleries for identification leads, and marketplace listings only for current supply and comparison—not as proof of identity. Facts are cross-checked when possible, and uncertainty is retained when the evidence is incomplete.
Access and review date
Core sources reviewed July 22, 2026. Marketplace inventory and database counts change continuously.