Denis Nowlan and Jane Dowd born c. 1800

My query is regarding the possibility that  my 3xsGreatgrandparents Denis Nowlan and Jane Dowd come from Co. Cork. Several years ago when visiting the Townland of Drombeg near Listowel in County Kerry where my GGrandfather William Nowlan (son of William Nowlan and Mary Walsh and grandson to Denis) was born in 1862 and grew up I was surprised to hear from a local Drombeg  resident that "it was said the Nowlans came from Cork".   Returning to NZ I heard back from some Australian family who remembered that  yes this had been rumoured in their family! 

I have searched in vain for a marriage for Denis Nowlan and Jane Dowd.  The first record I find for them is the birth of Mary Nowlan to Denis and Jane in 1824 in the Listowel Parish, Kerry.  In chronological order the next info I have is from their grandson Denis Nolan a well known Priest in Northern NY, USA who records in his 1910 census that his father (William my 2xsGGrandfather)) was born in India.  Then in 1834 I find the birth of Maurice Nowlan born in the 89th Regiment Barracks in Fermoy , Cork. One of his sponsors was a Mary Nowlan. On Find My Past I have found an 1830 birth in Madras  for a William Nowlan and these 3 births align for when the 89th Regiment was in Ireland and India then Ireland again.

I have not been able to find an Army Pension for Denis Nowlan so perhaps he left the army before the Regiment headed offshore from Ireland after 1834 and before he had been in the Army for at least 12 years.  Perhaps he stayed in Cork and raised his family there, and for this reason son William Nowlan did come from Cork but is this where his father Denis came from originally?

I have found a Dennis Nowlan and partners recorded in the Tithe Applotment Books for Knockduff, Cullen Parish, Co.cork  1825-1834 but this is the period when Denis was in the Army so perhaps unlikely this is him.  I have searched the Valuation Office Books but can not find him there.

I have found a Jane Dowd the sponsor in a 1856 Listowel baptism for a William Fitzpatrick from Limerick with mother Jane Nowlan (Jane is mentioned by her nephew Rev Denis in another place)  so have searched for birth and deaths for Jane Dowd in Listowel with no success.  But the fact that this baby was baptised in Listowel Parish when parents are recorded as living in Limerick, makes me think that perhaps Jane returned to her mother for her sons birth.  Which could mean that by then Jane Dowd was living in the Parish of Listowel.  And perhaps Jane originates from the Listowel area???

I wonder if some one might have some other ideas of what more I can do to find out more about Denis Nowlan and Jane Dowd and their children.

I have one puzzling piece of information about Denis's son William Nowlan (my 2xs Greatgrandfather) who married Mary Walsh and settled in the Townland of Drombeg.  Williams son Rev Denis was included in a book called Genealogical and Family History of  Northern New York, published 1910.  Denis has recorded his father William as "well educated, a skilled accountant and merchant" (he also records that his father William was born in 1834 in the East Indies  , when the family were already back in Ireland and it was Maurice born in 1834 and he mentions a daughter Jane but not the daughter Mary).  I am wondering how a son of an Army private would be given an education in Ireland enabling him to attain the position of Accountant and become a Merchant?  What I know is that they raised their family on a small farm in Drombeg from which they were evicted in 1889 (yes furniture thrown out on the road) after living there for 30 years.  Thankfully  the 1901 census records them  back living there so somehow things were resolved.  If William was an Accountant and/or merchant are there some records in Ireland that have these kind of records?

Many thanks for reading this til the end and in anticipation for any thoughts on how I can go forward.