Austin Shea, 1820s - 1840s

[moonmullins]

I am trying to find the family origins or birthplace of an Austin Shea who emigrated to the US from Ireland in 1848, age 24 +/-.  While I have not located his exact birthplace I did find that some likely nephews, Henry & Martin Shea, twins, were baptized in co. Mayo in 1851, sons of John & Rebecca Shea.  They had a younger brother Austin who was born in Dayton, OH, USA, in the same neighborhood where all these various Shea families lived. 

Would welcome any possible identification of Austin Shea, born in the early 1820s but no longer living in Ireland after 1848.