Regarding the swing out mechanism, it is a Needham Needle-fire gun. Again one was featured in the Emil Rosner part collection sold at Christies in November 2001.
For background on Joseph Needham, IGC has this:
Name William Needham
Other Names William Needham & Co; William & Joseph Needham; Joseph Needham & Co; J V Needham; Joseph & Henry Needham
Address1 Royal Hotel Yard, Temple Row, Birmingham
Address2 26 Piccadilly, London
Address3 26 Piccadilly, London; 108 1/2 New Street, Birmingham
Address4 26 Piccadilly, London; 27 Cannon Street, Birmingham
Address5 53 Piccadilly
Address6 1a Wilton Place, Knightsbridge
Address7 6 Park Side, Knightsbridge
City/Town Birmingham and London
Country United Kingdom
Trade Gun & pistol maker
Other Address Damascus Works, Loveday Street, Birmingham.
Dates 1842-1880
Notes
William Needham was born in 1801 but where he was born and who his parents were is not known. He appears to have been the elder brother of Henry Needham (b.1812 in Birmingham) who traded in Birmingham before moving to Vine Street in London. He also appears to have been related to Joseph Needham (b.1811) of Ashtead Row, Birmingham, who had a son named Joseph Vernon Needham (b.1836), the Birmingham gunmaker who was famous for the first successful ejector gun. In the 1841 census William was recorded living in Sherborne Road, Kings Norton, a few miles south of Birmingham. He was married to Suzannah (b.1801) and they had four sons and three daughters. His second son, Joseph was born in 1828 and became a gunmaker. William moved his business in 1841 to Royal Hotel Yard, Temple Row, Birmingham. On 24 June 1843 he patented a tube primer and special nipple (patent No. 9801 also covered under Scottish patent No. 103). In the same year a musket designed by him was rejected by the Board of Ordnance. In 1845 William moved to London where he opened at 26 Piccadilly trading as William Needham & Co. The name he used from 1849 to 1851 William Needham without the "& Co". In 1851 the name of the business changed to William & Joseph Needham, but this Joseph does not seem to have been his son who would have been 23 years old at the time, if it had been then the business is more likely to have been named William Needham & Son. The Joseph concerned appears to have been Joseph of Ashtead Row. It seems that this Joseph manufactured guns in Ashtead Row for William and possibly also for Henry who had moved to 4 Vine Street in London in 1849. Joseph was recorded in the 1841 census at Ashtead Row with his wife, Emma (b.1811), Joseph Vernon (b.1835) and Emily (b.1831). They were recorded in the 1851 census at 135 Ashtead Row by which time a second daughter was had been born. In the 1851 census Suzannah Needham was recorded at 26 Piccadilly as a widow so William had died. She was living with Joseph and George Henry and two of her daughters, and a few other more distant members of her family.
In 1851 W & J Needham exhibited at the Great Exhibition "A Patent Self-Priming Gun, Double and Single Guns to Load at the Breech, etc". On 2 October 1852 Joseph Needham of Ashtead Row, Birmingham registered patent No. 184 for a gun lock and the first successful hammerless needle-fire gun. He is known to have made needle-fire guns on the Rissack design. In 1850 Jean Jacques Rissack of Liege, Belgium patented a needle-fire gun in which the primer was in the base behind the powder as opposed to backing onto the over-powder wad, and the pin was either in the breech plug or on the hammer. Rissack's pistols and gallery rifles were very popular, the cartridges were made by Eley.
In 1853 the name of the London business was changed to Joseph Needham & Co. Henry was last recorded as a gun maker in 1856 at 5 Meards Court, Wardour Street. Almost certainly he died in that year and, because his son Henry (II) was only 14 years old, William took over his business on behalf of his mother Sarah. On 30 January 1865 J Needham and C H Russell registered patent No. 265 for a hinged and sliding breech block. In 1870 the name of the business at 26 Piccadilly changed to Joseph and Henry Needham by which date Henry (II) would have been 28 years old. Henry (II) however, later left the business and became a manufacturer of electroplated goods, returning to Birmingham by 1891 (see Henry Needham). The 1871 census records Joseph Needham as a 42 year old gun maker married to Eliza (b.1833 in Newbury, Berkshire) and living at 19 Orestan Road, Hammersmith. Their children were Helen L (b.1857), Kate (b.1858), Arthur J (b.1863), Horace C (b.1868), and Walter C (b.1869).
There seems to have been a great deal of co-operation between Joseph of Ashtead Row Joseph Vernon and Joseph & Henry Needham, but it is likely that it was primarily Joseph Vernon Needham's inventiveness that attracted the attention of W W Greener. In 1874 Greener bought the businesses of Joseph Vernon and Joseph and Henry Needham. In 1876 W W Greener moved the London shop to 53 Piccadilly. He continued to operate the London business under the name of Joseph & Henry Needham, but in 1878 moved the shop to 1a Wilton Place, Knightsbridge. In 1880 the London shop was at 6 Park Side, Knightsbridge, but after that date the Needham's apparently ran the business under the Greener name. The 1881 census records Joseph as a visitor staying with the Beddoe family at 12 George Street, Birmingham. His wife, Eliza, and Ellen, Kate, Arthur, Horace and Cecil were living at 14 Hammersmith Terrace. Arthur was described as a gun maker.
On 2 October 1883 George Henry Needham registered patent No. 4693 for a revolving chamber for drop-down guns and a butt plate safety mechanism. In the 1891 census Joseph and Eliza were recorded living at 6 Hammersmith Terrace, Hammersmith, with Helen L, Arthur J, Horace C and Walter C. Joseph described himself as a gunsmith, his sons were described as gunsmiths and workers in all metals. By the time of the 1901 census Eliza had died but Joseph was still living at 6 Hammersmith Terrace with Helen Louisa, Eliza Ann Kate, Arthur Joseph and Walter Cecil. Joseph described himself as a 72 year old living on own means. Horace C was not recorded but Arthur Joseph and Walter Cecil were described as brass workers on own account.
The only known records of the Needham firm exist in "Needham's Action Book" currently held by the firm of W W Greener. This book only covers the years 1886 to 1926 and serial numbers 1254 to 5000 and 6001 to 9892, lower numbers are known.
Here are the catalogue photos and description:
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Tim