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Many of the archives held in the National Archives are included in its on-line catalogue that can be searched for documents containing relevant references. It is available at this link: www.nationalarchives.ie/search-the-online-catalogue/simple#!/
As far as can be ascertained, the person to which the Deputy refers, died in 1920. I understand that a small number of archives are held by the National Archives that relate directly to the individual concerned. As the person died before the foundation of the State, material may also be available in National Archives at Kew in Surrey, the Archives Department in UCD, the Military Archives or local archives. It is possible that there may also be Compensation (Personal Injuries) records held by the Department of Finance.