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Jon R. Roma: Champaign interlocking machine without cover
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Jon R. Roma: Champaign levers
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Jon R. Roma: Champaign levers
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Jon R. Roma: Champaign levers
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Jon R. Roma: Champaign Tower operator's desk
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Jon R. Roma: Champaign Tower operator's desk
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Jon R. Roma: Champaign manipulation chart
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Jon R. Roma: Champaign manipulation chart
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Jon R. Roma: Champaign model board
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Jon R. Roma: Champaign replacement manipulation chartg
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Jon R. Roma: Champaign model board
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Jon R. Roma: Champaign power distribution board
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Jon R. Roma: IC's signal department at work
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Jon R. Roma: T. G. Shearer at Champaign Tower
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Jon R. Roma: Power distribution board at Champaign Tower
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Jon R. Roma: Champaign emergency release