Sometimes you need a bit of clarity....especially for slow people like me!
You are looking for this lot in any form prior to 1871 is that correct?
1881 census
7, Caves Terrace, Hammersmith, Fulham, Middlesex 
Susan C Crocker...Wife...55..Chronometer Makers Wife....Saffron Walden, Essex 
Walter J......".........Son...23.Comedian Unemployed  Stepney, Middx 
Edmond......".........Son...21...Draughtsman (Litho) Unemployed Mile End, Middlesex 
Marie.........."........Daur...18...Chronometer Makers Daur...Mile  End, Middlesex 
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1871 census
Rutland St, Stepney, Mile End Old Town, Stepney, London, Middlesex 
Samul C Crocker.....Head....60....watchmaker..................Mitford, Herts 
Susan C........."........Wife....48.........................................Saffron Walden, Essex 
Walter............"........Son.....16..electric telegraph student...Mile End, Middlesex 
Edmund.........."........Son.....13.............................................Mile End, Middlesex Mary..............."........Daur....11.............................................Mile End, Middlesex Joel................".........Son.....10..............................................Mile End, Middlesex Morris.............".........Son......8...............................................Mile End, Middlesex
Mary Cornell....Wife's Sister..45.wid..................................Saffron Walden, Essex 
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1851 census
Wills Alley, Saffron Walden, Essex 
William Cornell........Head....22...........Ag Labr.....................Ashdon, Essex 
Mary Ann...."...........Wife.....25............................................Ashdon, Essex 
John Smith..............Son.......5..............................................Ashdon, Essex 
Josiah Cornell...........Son.....2..............................................Ashdon, Essex 
Alfred Cornell............Son.....1 week.....................................Walden, Essex 
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Bryant