Regarding DNA TE Holroyd didn't have any sons did he? I don't think the DNA approach would be helpful in this case.
Here is James and Charlotte's marriage from Lancs OPC:-
Marriage: 4 Oct 1873 St Bartholomew, Salford, Lancs.
James Holroyd - 20 Warehouseman Bachelor of 9 Manchester Street
Charlotte Elizabeth Hall - 22 Spinster of 9 Manchester Street
Groom's Father: Joseph Holroyd, Clogger
Bride's Father: James Hall, Carder
Witness: Edwin Hall; Martha Hall
Married by Banns by: Saml. Evans
Register: Marriages 1869 - 1876, Page 131, Entry 262
Source: LDS Film 1786463