All that can presently (September 2019) be gleaned about Ed. C. Mahony from sheet music covers and by internet searching is that he has 7 works published between 1905 and 1913.
Of ragtime interest is Hypnotic Rag
(1912) published by Jos. M. Daly Music Co.
, Boston, Massachusetts, USA.
Surfers are welcome to contribute information about this composer.