John and Margaret Catherine Shea from County Kerry seeking birth and marriage records

I would like to find information for my 3x grand parents John and Margaret Katherine Shea. I could not find any records of her maiden name. Their daughter Mary Elizabeth obituary said she was born in County Kerry. I can not find any death records for John. I even checked the Diocese of the Catholic church in the but would like to find birth records. area with no success however the search years I gave to the archivist may be off so I will keep searching for his death

Here's what I have found. In US Federal Wisconsin census' 

1850  the birth year for John 1815, for Margaret Katherine 1810

1860 the birth year for John 1810, for Margaret Katherine 1801

1870  the birth year for John 1816, for Margaret Katherine 1793

1880 the birth year for John 1807, for Margaret Katherine 1798 

Margaret Katherine dies in 1883 and the newspaper post said she was almost 90 years old.

Their first child a daughter born March 1829 in Ireland. This might help with the marriage year.

They immigrated in about 1840. Two more daughters born in US 1845 and 1848

I would love to find parents of both John and Margaret Katherine and their marriage date and possible immigration records.

Thank you for any information

Renee