I don't have any specific info for you, but can tell you from personal experience it is often difficult to find people's Irish origin.
But, the best first advice is to try to find as much documentation you can for them in the US (assuming they were in the US since you mention the 1910 census) - perhaps something in those records will give you a clue that will allow you to jump the Atlantic to Ireland.
I've been doing the same thing myself, and still slogging away. I had been hoping my GGFather's NY Naturalization would give me what I needed, but it turns out those papers in 1885 don't record more than name, occupation and country.
You may have to get creative - don't forget if you run out of documents for them you can expand your research to other known or possible family members (or even friends) and one of their records might be of use.
Also don't forget to find and check gravestones, contemporary biographies and histories (Google Books or archive.org can be helpful.)
If you need help with what records might be available where they lived you should be sure to mention that info in this thread and perhaps someone who has experience researching there can give you some more specific tips.