According to his statement at the time of the 1911 census, he had had 2 children, both of whom were still living. You will find their names on "Family Search 1911".
His wife is shown as Maria Ellen, born Osmotherly.
He states he was born in London.
The William R Collier who died in 1941 was William Richard.
It looks as if Maria Ellen may have died in 1936, aged 66, registered in Leigh. On " Find a Will" Maria Ellen is described as a widow.
I cannot find William on the 1939 register.