Bored during a snowstorm on the East Coast of the US - came across your request.
My father - Francis (Frank) C. Cogger - came to the US from Castle Bar, County Mayo. (1950's). He is 75 now and residing in NJ. I believe that the Cogger family remaining in the Mayo county is my one uncle (Edward) and his children (my cousins.) (My cousins have told me that there are no other Cogger's around). Also, my father's sister resides in Dublin. My grandfather was Michael Cogger (not the same as yours given that he stayed in Ireland) - I have some info at my parents house when I was a child doing research (many years ago). I'll have to look it up if you need more. (Provided by great aunt - before she passed away - to me).
Good luck in your search.
Sharon Cogger
Middletown, NJ
