James Mather was a Brass Finisher, born Wigan. He is probably William's cousin or brother who was also a Brass Finisher from Wigan, and both came to live (and marry) in Elton.
In 1871, James and Elizabeth (32 & 37) were at 8 Ardwick Street, Salford with Walter (8), William (6, actually 1) and Sarah (1, actually 6). NOTE: On the census, the names of children William and Sarah are reversed (see GRO and 1881 census).
James died in 1880, leaving Elizabeth (49) a Widow in 1881 with Walther (18), Sarah (16), Willie (11), Elizabeth (7) and loger Maria Maden (25).