A Catherine Symondson is listed in the January to March 1883 death index age 48, Pancras district, volume 1b page 42.

[Why does he seem to use both James and Thomas as a middle name?]

In the 1841 census
Henry Symondson age 38, pianoforte ma [maker].
Wife Teresa age 40.
Son Alfred age 10,
son Henry age 9,
son Frederick age 7,
daughter Louisa age 5,
son? Teresa age 3.
All were born in the county of Middlesex. Civil parish St Pancras, Hundred Ossulstone (Holborn Division), Middlesex, Registration district St Pancras, sub registration district Regents Park. Living on Robert Street.

Listed in the 1851 census Address 3 Dean Street Civil parish Westminster St Margaret, ecclesiastical parish Westminster, Middlesex, England. Registration District Westminster, sub registration district St Margaret.
Theresa Symondson (or Symonson) widow, head, stationer, age 51, born in London. Son Henry Symondson age 18, born in London, occupation Music Seller.
Son Frederick Symondson age 17, born London, occupation Music Seller.
Daughter Therese Symondson, age 13, scholar, born London.
Daughter Marcella Symondson, age 9, scholar, born London.
[3 other families lived at this address as well, presumably on different floors.There are 5 floors today. I imagine their shop was on the ground floor and they lived above.]
[3 Dean Street is now a Tesco Store with address 2 to 4 Dean Street. Near Oxford Street.]
[Historical Note: Karl Marx (listed as Charles Mark) and his family were living at 28 Dean Street from 1851 to 1856]


Post Office Appointment Books
1855 Frederick Symondson, London, No. 2373

In the January to March 1856 marriage index Frederick James Symondson, Lambeth, Greater London, London, Surrey volume 1d page 352. Catherine Swan is also on the page.

Parish Records
St John’s Church Waterloo, Surrey, February 25, 1856
Frederick James Symondson, full age, Bachelor, Postman, Ann Street, father Henry Symondson, pianoforte maker
Catherine Swan, full age, Spinster, father David Swan, Mason
In the presence of G. Cleaver and C? D? Swan

London Illustrated News December 4 1858
North-Western District Post Office - A meeting of the letter-carriers was held in. the above office on Saturday evening last for the purpose of adopting measures for the formation of a permanent library. The chair was taken by Mr. Small, one of the senior letter-carriers, who enlarged upon the great benefits to be derived from the formation of a Literary society, more especially by the younger men of their body; the following officers were elected to carry the wishes of the meeting. Secretery, Mr. Symondson; Committee, Messrs. Dell, Small and Maddison. The Chairman was happy to be able to state the proceedings had the sanction of the Vice Controller and the Deputy Controller of the district. T. Boucher, Esq. and E. Finch, Esq., have promised their assistance.

From the 20 July 1860 London Gazette
Frederick Thomas Symondson, of No. 71, Warden road, Kentish Town, in the county of Middlesex, Pianoforte Maker and a Sorter in the North-Western District Post Office, having been adjudged bankrupt under a-Petition for adjudication of Bankruptcy, filed in Her Majesty's Court of Bankruptcy, in London, on the 11th of June, 1866, a public sitting, for the said bankrupt to pass his Last Examination, etc.

In the 1861 census living at 10 Weedington Road West, civil parish St Pancras, ecclesiastical parish Holy Trinity, Middlesex, Registration district Pancras, sub registration district Kentish town.
Frederick Symondson age 26, letter sorter G.P.O. born at St Pancras.
Wife Catherine age 26 born at St Pancras. Son Frederic age 5, born at St Pancras.
Son Henry age 3, born at St Pancras.
Son Adolphus age 1, born at St Pancras.
Mother Teresa Symondson, widow, age 62, school mistress born at St Pancras.

In the 1871 census living at 18 Weedington Road, St Pancras civil parish, London, Pancras registration district, Kentish Town sub-registration district.
Frederick T. Symondson, age 35, sorter in General P.O., born St Pancras Middlesex.
Wife Catherine age 35, born Westminster, Middlesex.
Son Frederick age 15, Telegraph Messenger, born at St. Pancras, Middlesex.
Son Henry age 13, Telegraph Messenger, born at St. Pancras, Middlesex.
Son Adolphus age 11, born at St. Pancras, Middlesex.
Son Claude W. age 8, born at St. Pancras, Middlesex.
Son Alfred V. age 7 born at St. Pancras, Middlesex.
Son George L. age 2 born at St. Pancras, Middlesex.
Son newly born 2 days no name, born at St. Pancras, Middlesex.

London electoral Registers 1875, 1881
Frederick Symondson, 18 Weedington Road, Marylebone, St. Pancras

In the 1881 census living at 18 Weedington Road, St Pancras civil parish, London, Pancras registration district, Kentish Town sub registration district.
Frederick T. Symondson, age 46, professor of music, born Middlesex.
Wife Catherine Symondson age 46 born Middlesex.
Son Frederick J. Symondson, age 25, letter carrier. born Middlesex.
Son Adolphus Symondson, age 21 pianofort maker born Middlesex.
Son Claude W. Symondson, age 18, clerk born Middlesex.
Son Alfred V. Symondson, age 17, warehouseman born Middlesex.
Son George L. Symondson, age 12 born Middlesex.
Son Percy A. Symondson, age 10, born Middlesex.
Daughter Kate M. Symondson, age 7, born Middlesex.
Son Horace D. Symondson, age 4 born Middlesex.

In the January to March 1882 death index Frederic? Thomas Symondson, age 47 Pancras district volume 1b page 143

In the National Probate Calendar
8 April 1882. Administration of he Personal Estate of Frederic Thomas Symondson late of 16 Weedington - road Kentish Town in the County of Middlesex who died 23 March 1882 at 16 Weedington-road was granted at the Principal Registry to Catherine Symondson of 16 Weedington-road Widow the Relict. Personal Estate 120 pounds.