Both his mother's and father's Probate names a son "William Wallace Finlayson" so this must be the son to whom they were referring.
The 1861 Census found the family in Hillingdon, Middlesex, England.[2]
Sources
↑ FINLAYSON, - Mother's Maiden Surname: DYER GRO Reference: 1853 J Quarter in UXBRIDGE UNION Volume 03A Page 24
↑ "England and Wales Census, 1861," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:M76C-MVW : 13 August 2020), William Finlayson in household of William Finlayson, Hillingdon, Middlesex, England, United Kingdom; from "1861 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO RG 9, The National Archives, Kew, Surrey.
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