And interestingly the 1881 suggesting he was enumerated as Wm H which lends weight to it being your man
1881 Scotland Census about Euphemia Barker
Name: Euphemia Barker
Age: 28
Estimated Birth Year: abt 1853
Relationship: Wife
Spouse's name : Wm Barker
Gender: Female
Where born: Glasgow, Lanarkshire
Registration number: 644/6
Registration district: St Rollox
Civil parish: Glasgow Barony
County: Lanarkshire
Address: 44 Glebe St
ED: 30
Household schedule number: 50
Line: 15
Roll: cssct1881_229a
Household Members:
Name Age
Wm Barker 31
Euphemia Barker 28
Annie L Barker 5
Wm H Barker 3
Philirn Barker 29
Walter Forsyth 34
Parish: Glasgow Barony; ED: 30; Page: 10; Line: 15; Roll: cssct1881_229a.
I should have said that its imperative that you check the original page images for these census as transcription errors are rife
They will be available on scotlandspeople
Nivard Ovington in Cornwall (UK)