Stelfox contends that O'Mahony had considerable duties and at times had sole responsibility for the zoological collections, despite never rising above the position of Technical Assistant which was the lowest grade of staff in the museum and never receiving an increase in his salary.

After Stelfox retired in the late 1940s his duties again increased, and despite University College Dublin awarding him a Masters in Science for his published work, the museum only offered him a permanent post as a Senior Attendant after colleagues and peers had lobbied the Minister for Education, Richard Mulcahy.

He also volunteered with the precursor to the Irish Navy from 1939 to 1945, and was awarded a non-commissioned rank of a Chief Petty Officer and Instructor in the Maritime Inscription Corps.

O'Mahony was a nationalist, and had a number of portraits to the leaders of the Easter Rising in his museum office, and in his youth he had guarded IRA weapons dumps in sandhills on Dublin Bay.

The collection is accompanied by manuscript material including a notebook titled 'Records of beetles in Co. Dublin (North East)' and there is some correspondence.

This was despite the collections being amassed during their official duties, and Beirne surmised that this was in retaliation to the perceived poor treatment that O'Mahony and Stelfox received during their careers at the museum.