John Mitchell m. Mary Pelketon

I am trying to trace Mitchell ancestors from Offaly.I have come to a dead end in my research.

My Great GrandfatherPeter Mitchell, was a blacksmith/iron worker. After some research I founda Peter Mitchell (bap.1852 Kilcormacson of John Mitchell & Mary Pelketon)whomarried Bridget Tiquin (b.1860)in Frankford 1886,and they had at least 3 children all born in Pallas - Mary (b.1890), Bridget (b.1892),John (b.circa 1895). John born c1895 was my grandfather, though my father never knew him.

John Mitchell bc1895 joined the Leinster Regtand later can be traced serving with the Royal Artillery inEngland around 1918, 1919.
By 1920 he had met and married my grandmother in London, and by 1928 he disappeared off the face of the earth leaving her and their baby son, my father.

Johns father,Peter Mitchell, also came to UK. I found a 1922 death record which would seem to be him...Coathill Hospital,Lanarkshire Scotland,....Peter Mitchell, iron worker, widower of Bridget T-. Age 68, father:John Mitchell. Mother:Mary Mitchell MSPelkinton.

But my problem is in managing to getback further with thisMitchell family, ie Peter Mitchells parentsJohn Mitchell & Mary Pelketon who married in Kilcormac parish in1845

Is anyone else researching this family? I could do with some help please.