A bit more progress... (and I think, based on finding no other Skarine families in Cork, Limerick or Dublin, so far, that Nicholas did come from Sweden himself).
Did a timeline to see what was missing etc. which shows where the family lived- Cork 1862-c1864, Limerick 1867-1870 then Dublin 1873- .
1862 Nicholas Skarine (father Gerhard?) m. Susan Halanan
c1863? Helena Skarine born Cork
c1864 Engla Skerine born Cork
1867 Thomas Nicholas Skarine born Limerick
?1867 Tuscar Caroline Skarin died Limerick age 0
1868 Nicholas Skarine age 0 died Limerick (possibly Thomas Nicholas born 1867)
1869 Nicholas Gerhard Skerine born Limerick (Georges Quay, father Nicholas boot & show maker) died 1870 Limerick
1869 Nicholas Skarine died
1870 Takla Aurora Skarin born Limerick
1873 Josephine Skeerine 23 Essex St. East Dublin (possible death in 1873 also Dublin South)
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1873/03174/2164314.pdf 1878 Nicholas Skarine age 56, married, bootmaker, died Dublin
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1878/020513/7198374.pdf 1887- Helena Skerine (9 Windsor Terrace, father Nicholas) m. Patrick Robert McGrath
1910 Susan Skerine died Dublin
1941- Engla D. Skerine died Dublin
1955 Thecla A. Skarine death Jan./Mar.1955 Wandsworth district (London)