Your belief that Thomas's background is Danish is family knowledge. Can you expand on that? Could that be referring to grandparents of Thomas? Can you find out more?
The informant on Thomas's death record is granddaughter Mrs. Robert Mouilaws (? hard to read).
She gives his parents' names as Thomas Splan born Ireland and Elizabeth Wuerton (? hard to read) born England.
Ontario, Canada, Deaths, from Ancestry.com Name: Thomas Splan Death Date: 4 Apr 1928 Death County or District: Bruce Age: 87 Gender: Male Estimated Birth Year: abt 1841 Birth Location: Ontario
Ontario, Canada, Marriages Name: Thomas Splan Birth Place: Canada Residence: Hullett Township Age: 22 Estimated Birth Year: abt 1841 Father Name: Thomas Splan Mother Name: Elizabeth Spouse Name: Elizabeth Westin Spouse's Age: 18 Spouse Birth Year: abt 1845 Spouse Birth Place: Canada Spouse Residence: Goderich Township Spouse Father Name: George Westin Spouse Mother Name: Ellen Marriage Date: 10 Mar 1863 Marriage County or District: Huron
In his married life Thomas appears in the census records but the earliest I find him is 1860
1860 Canada census Name: Thomas Splan Gender: Male Age: 20 Birth Year: 1841 Birthplace: Canada Home in 1861: Goderich, Huron, Canada West Religion: Church of England Film Number: C-1035-1036 Page Number: 37
Another marriage - a brother? Ontario, Canada, Marriages Name: Richard Splan Birth Place: Kincardine, Ontario Age: 21 Estimated Birth Year: abt 1853 Father Name: Thomas Splan Mother Name: Elizabeth Weston Spouse Name: Ann Jane Elliott Spouse's Age: 19 Spouse Birth Year: abt 1855 Spouse Birth Place: Kincardine, Ontario Spouse Father Name: Robert Elliott Spouse Mother Name: Sarah Waldron Marriage Date: 19 Jun 1874 Marriage County or District: Huron