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| Antique 415a Keuffel & Esser N-4100 patent 1900 slide rule |
| 415a |
| $50.00 |
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Slide Rule has Pat. June 5 1900 N-4100 Keuffel & Esser NY made in USA on it there is a small crack on the wood at one end cate also has patent applied for on it with previous owners name. More pictures upon request. |
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