RE: 1821-1851 census returns almost destroyed in a fire, and Peter Coyle (County Donegal)

Where can I find these 1821-1851 census records for County Donegal (for Coyle surname) that were almost destroyed in a fire?  Thank you.

My sister and I were in County Donegal in May, looking for "our" Peter Coyle.  We visited Glenieraragh/Glen/Mevagh, 1 of the 4 locations in Griffith's Valuation that lists a Peter Coyle in County Donegal (we located Anthony Coyle, but he was unavilable).  However, Griffith's was publishd after the time Peter Coyle left Ireland for the U.S. in 1847.  We were also in Dunfanaghy, Ramelton, Milford, and Rathmullan, among other places, trying to find Peter Coyl who was born in 1796 (married in Ireland to Catherine Coyle; possible maiden name:  Cavan or Kavan).  Peter came to the U.S. at age 50.  He had a son who was also named Peter Coyle, born in Ireland in approvimately 1836, who appears to have come to the U.S. after 1847.

A Peter Coyle shows up as a defendant (overholding) in an 1829 Civil Bill Ejectment in Kilmacrenan, Raymunterdony (Richard Benson was the Plaintiff).  It Is possible that this is our Peter Coyle, because he was still in Ireland at the time.  The location of the land in question (Peter Coyle's are listed in Carrowcanon/Cross Roads in the 1901 Census) was 4 miles S.W. of Dunfanaghy (possibly, Fawnmore to Falcarragh).

Aside from the Peter Coyle's mentioned above (Griffith's) in Mevagh and Raymunderdoney, the other 2 County Donegal Peter Coyle's listed are Lurgacloghan/FanadWest/Clondavaddog/Millford/Kilmacrenan; and Roughpark/Aughnish/Millford/Kilmacrenan.

We assume Peter would have had brothers and sisters who may have remained in Ireland.  However, after approximately 10 years of intermittent searching for Peter (and Catherine Coyle), we have not been able to definitely locate where in County Donegal he lived.  We have a great deal of U.S. information, but we don't have any County Donegal data, such as the name of relatives who may have remained in Ireland, or his Catholic Church, birth certificate or marriage certificate.  We believe he was a farmer before he came to the U.S.

We would also like to know if Peter Coyle was in the Dunfanaghy Workhouse.  

We did attend the Coyle clan gathering in Ballyliffin (and had a wonderful time), although we have not yet found whether we are related to the Inishowen Coyle's.

If anyone has an ideas on finding our Peter Coyle, I'd appreciate hearing from you.  Thank you, again.

Helen (Coyle) Haskins, St. Louis, MO, U.S.A.