I wonder if this Gilbert might be the right one ... don't have any details, spouse or descendants for him, but there are some similarities.
Porteous family #1150 (s/o John PORTEOUS & Ann BROWN): 1 Christopher PORTEOUS b: 1826 Glasgow, LKS SCT d: 1906 Elie, FIF SCT m: 1855 Liverpool, LAN ENG .+Jessie Kerr McFAYDEN b: 1838 Glasgow (Everton?), LKS SCT d: 1905 Partick, LKS SCT .2 Gilbert PORTEOUS b: 1858 IRL d: 1912 .2 Thomas McBride PORTEOUS b: 1873 Anderston (Glasgow), LKS SCT d: 1900 Kelvin, Glasgow, LKS SCT
Not sure if above looks likely or if you know any more details about Gilbert ... don't seem to have anyone by that name b: 1860-65 on file.Only other one close is b: 1857 Anderston, Glasgow, LKS SCT, s/o Gilbert PORTEOUS & Martha McCOLL (no further detail).
slainte! Pat A. Winnipeg, Manitoba, Canada Volunteer Research Contact for . . . The Porteous Associates