Definition of Fellmonger: one who removes hair or wool from hides in preparation for leather making. British. Merriam-Webster

In the October to December 1871 death index John Costello, age 44, Sheffield registration district, Yorkshire volume 9c, page 323

Parish records Manchester Cathedral
Baptism June 10, 1827 Frances Blakeborough daughter of John and Mary Blakeborough of Manchester, father is a picker maker, by W.D. Wray, Chaplain.

Parish records St. Peter, Great Bolton, Lancashire
Marriage August 9, 1846 John Costello, minor, bachelor, skinner, residence Great Bolton, father Miles Costello, upholsterer and Frances Blakeborough, minor, spinster, residence Great Bolton, father is John Blakeborough, picker maker, after banns by ? ? Loxham, Curate, in the presence of William Sharples and James Si???ot.

In the 1851 census No. 20 Water Side, Little Bolton, Lancashire.
Head John Costello, age 22, fell monger, born Manchester, Lancashire.
Wife Francis Costello, age 22, born Manchester.
Son James Costello, age 3 , born Bolton, Lancashire.
Daughter Emma Costello, age 2, born Bolton.
Son John Costello, age 1, born Bolton.

In the 1861 census Well Lane, Little Bolton, Lancashire.
Head John Costello, age 33, skinner (operative added later), born Manchester, Lancashire.
Wife Fanny Costello, age 30, born Bolton. [Must be an error.]
Son James Costello, age 14, timekeeper (Cotton Mill added later), born Bolton.
Daughter Emma Costello, age 12, hooker of cotton cloth, born Bolton
Son John Costello, age 10, hooker of cotton cloth, born Bolton.
Daughter Fanny Costello, age 9, born Bolton.
Son Alfred Costello, age 6, born Bolton.
Daughter Alice Costello, age 4, born Bolton

In the 1871 census No. 20 Neepsend Lane, Brightside, Yorkshire.
Head John Costello, age 43, fell monger, born Manchester, Lancashire.
Wife Frances Costello, age 42, born Manchester.
Son James Costello, unmarried, age 22, driller for engines, born Bolton, Lancashire.
Son Alfred Costello, age 15, wood sawyer, born Bolton.
Daughter Alice Costello, age 13, born Bolton.
Daughter Jane Costello. age 7, scholar, born Bolton.
Son Frederick Costello, age 4, scholar, born Sheffield, Yorkshire.
Grandson Henry Capper, age 1, born Sheffield.
Visitor Sarah ??? Heath, age 30, born Owlerton, Yorkshire.
Visitor’s son George Henry Heath, age 3 weeks, born Sheffield.

In the July to September 1872 marriage index Frances Costello and Jacob Walton are on the same page Sheffield, Yorkshire, volume 9c, page 368.

In the 1881 census 21 Neepsend Lane, Brightside Bierlow, Yorkshire.
Head Frances Walton, married, age 49, born Manchester Lancashire.
Son Alfred Costello, unmarried, age 25, steel melter coker, born Bolton Lancashire.
Daughter Jane Costello, age 17, iron casters cors? maker, born Bolton.
Son Frederick Costello, age 14, steel roller, labourer, born Sheffield, Yorkshire.
Daughter Mary Ann Walton, age 13, born Sheffield.

In the 1891 census 21 Neepsend Lane, Brightside Bierlow, Sheffield, Yorkshire
Head Head Thomas ? Fearnley, age 40, metal caster, employed, born Manchester, Lancashire.
Wife Alice Fearnley, age 34, born Bolton, Lancashire.
Son Harry W. Fearnley, age 16, metal caster, employed, born Bolton.
Son John T. Fearnley, age 13, metal caster, employed, born Sheffield.
Daughter Frances Fearnley, age 11, scholar, born Sheffield.
Daughter Alice Fearnley, age 9, scholar, born Sheffield.
Son Robert Fearnley, age 7, scholar, born Sheffield.
Son William Fearnley, age 5, scholar, born Sheffield.
Son Jervis Fearnley, age 4 months, born Sheffield.
Lodger Alfred Costello, single, age 37, brush maker, employed, born Bolton, blind 8 years. [brother to the wife]
Visitor Frances Walton, widow, age 62, born Manchester. [mother of wife]
Visitor Beatrice Woods, single, age 15, born Manchester.
Visitor Harry Woods, age 11, scholar, born Manchester.
Visitor Edith Woods, age 9, scholar, born Sheffield.

National Probate Calendar
Francis Walton of 21 Neepsend Lane Sheffield widow died 19 January 1892 Probate Wakefield 18 May 1892 to Edward Llewellyn Dean draper. Effects 153 pounds.