My collections aren't much use for this as they generally only go up to 1851 (the date of the first reliable census). However, I've been able to establish that Andrew's mother was Margaret Walker.
Find My Past has the following Statutory Register of Births entry:
First name(s) Andrew
Country England
Last name Morton
Volume 10B
Birth quarter 2
Page 79
Birth year 1874
Record set England & Wales Births 1837-2006
Mother's maiden name Walker
Category Birth, Marriage, Death & Parish Records
District Newcastle upon Tyne
Subcategory Civil Births
County Northumberland
Collections from Great Britain, England
I have checked several of his siblings' births and they all show the mother's maiden name as Walker.
The Register of Marriages has:
First name(s) Margaret
Country England
Last name Walker
Volume 10B
Marriage quarter 4
Volume as transcribed 10B
Marriage year 1856
Page number 80
Registration month -
Record set England & Wales Marriages 1837-2005
MarriageFinder™ Margaret Walker married one of these people
Ralph Archer, Andrew Murton
Category Birth, Marriage, Death & Parish Records
District Newcastle upon Tyne
Subcategory Civil Marriage & Divorce
District number -
Collections from Great Britain, England
County Northumberland
It's therefore safe to conclude that Andrew's Grandfather was John Morton as per my previous post:
Andrew son of John and Anne Murton, Pilgrim Street, Tailor, baptised 28 January, 1835 at Newcastle All Saints
As a matter of interest John was previously married to Margaret Richardson who died around 1831/32 (no trace of a burial)
John Murton, of this parish and Margaret Richardson of this parish, by Banns, married 19 May, 1816. Wit. James Richardson, Thomas Morland - Newcastle All Saints
Hope this helps.
Andrew