I've found a page from the 1881 census with Peter Salter, listed here as aged 78 Packing Case Maker as you stated:

Peter Salter Household -DO CLICK THIS FOR HIS HOUSEHOLD WHEN ONLINE
Male

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Other Information:
Birth Year <1803>
Birthplace Shoreditch, Middlesex, England
Age 78
Occupation Packing Case Maker
Marital Status W <Widowed>
Head of Household James B. SEARLE
Relation Lodger

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Source Information:
Dwelling Heneage St St Thomas Chambers
Census Place London, Middlesex, England
Family History Library Film 1341095
Public Records Office Reference RG11
Piece / Folio 0439 / 33
Page Number 1



and for research I strongly recommend the page: http://www.familysearch.org/Eng/Search/frameset_search.asp?P...
to all genealogists with recent British ancestors, The 1881 census online, where you can see details of whole households. I would like to be able to relate our Salter families. My Frederick Salter was born in Maidenhead, Berkshire in 1825 and he seems to have had frequent business in London, since he was a Wheelwright. I hope we find a link otherwise I need to further consider Berkshire Salters. Good luck and Thanks for your help
Adam