The will of silver spoon manufacturer Robert Henry Walliss of 6 President Street East, King Square, in the parish of St Luke, Middlesex, was signed on 14 June 1852 and proved in the Prerogative Court of Canterbury in 1853 (
http://discovery.nationalarchives.gov.uk/details/r/D13577).
His gravestone at Abney Park Cemetery, Stoke Newington, shows that he died in July 1852 aged 58 (
https://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=84819247&ref=acom) but his age was recorded as 57 when the death was registered (
https://www.gro.gov.uk/gro/content/certificates/Login.asp).
The will provides for his children Henry Robert Walliss (£150), Frederick Walliss (£550 + various household goods, including several specified silver items), Amelia Walliss (to be kept at school until aged 15) and Charles Walliss (executor, residual legatee and guardian of sister Amelia). Also mentioned are the testator's brother George Walliss (£19 19s.) and Doctor Campbell of Tabernacle House, Moorfields (£19 19s.). [John Campbell (1795-1867) was a Congregationalist minister -
https://en.wikipedia.org/wiki/John_Campbell_(minister).] Silversmith Robert Death of Wellington Street, St Luke, was to receive 19 guineas for his trouble as executor but he does not appear to have acted in that capacity.
I wonder whether Robert Henry Walliss was the son of "Wallis" and Sarah Wallis who was born on 19 Nov. 1794 and baptized as Robert Wallis at St Luke, Old Street, Finsbury, on 21 Dec. 1794 (
https://familysearch.org/ark:/61903/1:1:JMJH-899).