James died between 1861 and 1871. The only Lancashire date match is at Poulton-le-Fylde, Blackpool, aged 41, which seems unlikely unless he was on his holidays (a popular holiday destination). The only local death is in 1871. This is possible as death is before the census.
Lancashire Death indexes for the years: 1871 MATHER James 50 Heywood, Rochdale H/29/49
MATHER, JAMES 50 GRO Reference: 1871 M Quarter in BURY LANCASHIRE Volume 08C Page 291
General Notes
In 1841, James (15) was with his mother Fanny (45) at Clough Lane, Newchurch.
In 1851, James and Jane Mather (26 & 25) were at Baltic, Newchurch, Haslingden (no children).
In 1861, James and Jane Mather (35 and 35) were in Cowpe, Rossendale, Haslingden (no children).