I saw your post and I thought I could help. You are wanting info on Lyttle Dunkin b. 1775 and is he the father of Lytle Duncan b. 1804 . Well I did find a Lytle Duncan Not a Dunkin but the dates are wrong and I try to find him but not with that D.O.B. But I did find something that might help:
Tithe Applotment Books 1823-1837 Information from many of these books are online at http://www.irelandxo.com/
But I did find this on Family Search.org Lyttle Dunkin B. 1777 Sallaghan, Killishandra, Cavan, Ireland married to Sarah Dunkin born 1784 Sallaghan,Killashandra,Cavan,Ireland. died 29 Oct 1866 Crosthwaite Park, Kingstown, Ireland Dublin Ireland.
Sources : Ireland, Civil Registration Deaths Index, 1864-1958 ancestry. com
Web: Ireland Burial Index, 1600 -1927 ancestry.com
https://familysearch.org/ark:/61903/2:2:3FY-LHC: accessed 6 Aug.2018 entry for Sarah Dunkin, sources, "Duncan RE" file (2:2:2: MM6H-3J2) submitted 29 Jan 2018 by Robert Duncan 6(Identity withheld for privacy).
CHILDREN OF LYTTLE AND SARAH DUNKIN: ARE AS FOLLOW:
1. LYTLE DUNCAN B. 1804 IRELAND AND DIED 24 DEC. 1872 BOHEY, LEITRIM, IRELAND. WIFE - SARAH JACKSON B. 20 SEPT 1807 LIMERICK, IRELAND DEATH----7 jAN 1874 BOHEY, LEITRIM, IRELAND OR MANOR HAMILTON, IRELAND.
BAPTISM 9 NOV 1806 SAINT MARY'S INDEPENDENT, GLOSSOP, DERBY, ENGLAND PARENTS ARE: THOMAS JACKSON AND MOTHER-SARAH.
2.JOHN DUNCAN B. 1813 LEITRIM , IRELAND AND DIED----SEPT 1903 DARK VALLEY, MANOR HAMILTON, IRELAND. SPOUSE; SARAH WITHERS B. 1831 SLIGO, IRELAND DIED---6 APRIL 1903 DARK VALLEY, MANOR HAMILTON, LEITRIM, IRELAND
RESI 1859 LEITRIM,IRELAND.
3 JAMES Duncan B. 1820 BOHEY, MANOR HAMILTON, IRELAND - NO WIFE LISTED.
SOURCES; IRELAND CIVIL REGISTRATION DEATHS INDEX 1864-1958 ANCESTRY. COM
IRELAND SELECT MARRIAGES 1619-1898 ANCESTRY.COM
WEB:IRELAND CENSUSES 1901 ANCESTRY.COM
WEB: IRELANDCENSUS SEARCHFORMS 1841-1851 ANCESTRY.COM
ANCESTRY FAMILY TREES -ANCESTRY.COM
"Pedigree Resource File" database FamilySearch
sources; Duncan RE" file (2:2:2:MM6H-3J2, submitted 29 Jan 2018 by Robert Dunkin
CHILDREN OF LYTTE DUNCAN B;.1804 AND SARAH JACKSON B. 1807 ARE AS FOLLOWS;
1. THOMAS DAVIS B. 29 OCT 1827- GLENBOY CLOONCLARE, IRELAND DIED13 OCT.1902 DUFFERIN,ONTARIO, CANADA.
RESIDENCE - 1871, 1881, 1891, 1901 AMARAMT, WELLINGTON,ONTARIO, CANADA. PARENTS ARE JOHN DAVIS AND MARY WILLIAMSON.
SPOUSE; FRANCES DUNCAN BORN 11 JAN 1829 LEITRIM,IRELAND. MARRIED 4 OCT 1854 LEITRIM,IRELAND. DEATH--27 APRIL 1906 SHELBURNE DUFFIN, ONTARIO, CAN ADA
2/ MARY DUNCAN B. 3 MARCH 1831 BOHEY, LEITRIM ,IRELAND DIED 12 MARCH1844 LEITRIM, IRELAND. NO SPOUSE LISTED.
4. JAMES DUNCAN B. 1 FEB 1832 BOHEY,LEITRIM IRELAND OR 11 JAN 1829 IRELAND DIED 25 APRIL 1868 PHILADELPHIA, PA
1850 PHILADELPHIA NORTH MULBERRY WARD PHILADEPHIA PA
IMMIGRATION 4 MAY 1849 NO SPOUSE LISTED
5. JOHN DUNCAN B.2 FEB 1832 BOHEY, LETTRIM CO.IRELAND DEATH ;---14 OCT1906 NEW MILFORD,LITCHFIELD CO. CT.
1871 RESO- ONTARIO,CANADA,
1880. 1900 RESI LITCHFIELD,CT.
WIFE --- ELIZA ALLINGHAM BORN 19 FEB 1841;LEITRIM,IRELAND. DEATH 6 JAN 1933 LITCHFIELD CO. CT.
1910 RESI - LITCHFIELD, CT.
6. RICHARD DUNCAN B. CARRICK, IRELAND IN 1824 AND DIED 16 MAY 1899 ONTARIO, CANADA
BURIAL; SHELBURNE DUFFERIN CO,ONTARIO, CANADA.
RESI - YORK WEST
1871 RESI - ONTARIO, CANADA
1891 RESI- AMARANTH, WELLINGTON NORTH , ONTARIO, CANADA.
IMMIGRATION- EMIGRATION 1867 YORK TOWNSHIP, CANADA.
SPOUSE ELIZABETH (ELIZA) DUNCAN B. 27 MARCH 1834 BOHEY LEITRIM, IRELAND AND DIED 4 JUNE 1913, YORK, ONTARIO, CANADA.
BURIAL - SHELBURNE, DUFFERIN , ONTARIO CO.CANADA.
1911 RESI - TORONTO EAST, ONTARIO,CANADA
7 JOHN JAMESON B. 1837 BOHEY, LEITRIM IRELAND DIED MARCH 1895 BELFAST, IRELAND (FATHER FRANCES JAMESON) MARRIAGE 7 JAN 1861 LEITRIM IRELAND TO MARY DUNCAN B. 11 JAN 1837 LEITRIM IRELAND. DIED NOV 1914 INISHOWEN,IRELAND.
RESI 31 MARCH 1901 ARRAN QUAY, DUBLIN, IRELAND. ALTERNATE NAME: MARY A JAMESON/JAMISON.
8. WILLIAM DUNCAN B. 24 JUNE 1838 IRELAND D. 2 JUNE 1905 LITCHFIELD CT.BURIAL: LITCHFIELD CT.
1880, 1900 LITCHFIELD, CT.
SPOUSE: ANNA MEEHAN B. 24 NOV 1838 IRELAND OR 1842 LEITRIM IRELAND OR NOV 1839 LEITRIM IRELAND DIED 28 APRIL 1922 NEW MILFORD, CT, BURIAL ;NEW MILFORD,CT.
9. JACKSON DUNCAN B. 2 JUNE 1839 OR 1845 LEITRIM IRELAND D. 12 OCT 1918 BOHEY,LEITRIM,IRELAND.
RESI 1901, 1911 CLOONLOUGHER,LEITRIM,IRELAND WIFE; ELIZA DUNDAS -BORN 15 SEPT 1839 -1848 DUFFERERIN, CASTLE, CAVAN IRELAND. DEATH 22 FEB 1915 MANOR HAMILTON, IRELAND
RESI 1901 LEITRIM, IRELAND
RESI - CORK HILL
BAPTISM 26 DEC 1846, KINSALE,CORK,IRELAND.
ALTERNATE NAME: ELIZA DUNDASS DUNCAN
PARENTS----ROBERT DUNDAS AND MOTHER - MARY BRIEN.
MARRIAGE 2 AUG. 1865 BOHOE,FERMANAGH,IRELAND.
10 JOHN ALEXANDER DUNCAN B.13 SEPT 1830 OR 1840 BELFAST ANTRIM, NORTHERN IRELAND.OR BORN ABT 1834 ANTRIM, NORTHERN IRELAND
DIED - 6 MARCH 1897 TORONTO,ONTARIO, CANADA
BURIAL TORONTO MUNICIPALITY, ONTARIO,CANADA
WIFE; - SARAH DUNCAN BORN 25 SEPT 1841 OR 1843 LEITRIM, IRELAND, DIED 15 APRIL 1916 -TORONTO,ONTARIO,CANADA
BURIAL TORONTO,TORONTO MUMICIPALITY,ONTARIO,CANADA.
11.GEORGE DUNCAN B. 1 SEPT1843 cARRAIGEENCORE, IRELAND DIED - 28 MARCH 1912 KINGS NEW YORK
RESI 1865 MONROE,NY
RESI 1870 BROOKLYN WARD 5, KINGS, NY
RESI 1871 POPLAR, LONDON, ENGLAND
1892 BROOKLYN , KINGS,NY
1905 - BROOKLYN KINGS, NY
1910 - BROOKLYN WARD 20 KINGS, NY
WIFE - ANNE SKELLY OR ANNE S. KELLY BORN 1846 NEW YORK DIED 30 APRIL 1905 KINGS NY
1860 NEW YORK WARD 21 DIST 5 NEW YORK
12. LYTLE DUNCAN B. UNK DIED 26 MARCH 1900 FERMANAGH, IRELAND
MARRIED SUSANNA (SUSAN) DUNCAN ON 31 JULY 1865 LEITRIM IRELAND. BORN 1 JAN 1845 LEITRIM, IRELAND AND DIED 4 APRIL 1895 DARK VALLEY LEITRIM, IRELAND.
13. HENRY DUNCAN B. 1847 IRELAND DIED 1 DEC, 1875 NEW MILFORD CT. BURIAL NEW MILFORD CT
RESI ST. LOUIS WARD 11 , ST LOUIS, MISSOURI
RESI 1 JULY 1863 NEW YORK
WIFE; HANNAH ALLINGHAM B. 2 JULY 1843 BOHEY IRELAND DIED 23 DEC 1932 LITCHFIELD, CT.
RESI 1930 LITCHFIELD CT.
PARENTS; ROBERT ALLINGHAM AND GRACE HILDAGARDE, ALLINGHAM.
14. LYTLE DUNCAN B. NOV 8, 1848 BOHEY, LEITRIM, IRELAND
DEATH 7 SEPT 1914 ONTARIO, CANADA
BURIAL TORONTO MUNICIPALILITY, ONTARIO CANADA
ALTERNATE NAMES LYTTLE, DUNCAN, PARENTS ARE LYTLE DUNCAN AND SARAH JACKSON.
MARRIED 13 OCT 1874 ONTARIO CANADA TO MARY ANN (MINNIE A ) MCINTYRE B. 19 JULY 1850 ONTARIO CANADA, DIED 26 FEB 1921 TORONTO ONTARIO,CANADA
ALTERNATE NAME MINNIE A DUNCAN
PARENTS; ---ROBERT MCINTYRE,AND JANE CAMPBELL
I HOPE THIS HELPS I GOT ALL OF THIS ON FAMILYSEARCH.ORG FAMILYTREES.COM AND IF YOU NEED MORE HELP JUST LET ME KNOW. NANCY