Do you have Census records for this family.
I have found Frederick in 1861, apprentice Shoemaker.
Thomas, age 8 and Frederick aged 6, both born Luton, are in the workhouse in 1851 Census.
1841 Census
North Place
Luton, Bedfordshire
HO107/4/19/Luton
John BENNETT, 33, Baker, Born in County, yes
Sarah, 30, NOT born in County
Ann, 9, yes
John, 5, yes
Edward, 3, yes
Benjamin, 1, yes
Benjamin BENNETT, 14, Apprentice Baker, yes
Benjamin ADAMS, 25, Shoemaker, no
Extra child Benjamin and other Benjamin must be the cousin? As 1841 relationships not shown difficult to know.
EDWARD BENNETT
In 1841 Edward is at home with parents
1851 a servant in the Flemons household, Leighton Buzzard
1861 He is married to Elizabeth, with son Frederick age 1. He is a Miller living in Marsworth, Buckinghamshire. Also in household is James PEARSON, grand-father, Miller age 75.
1871 Elizabeth is now Mary.E, same pob though, extra Child Sarah, born 1863
1881 Still in Bucks, corn miller, children still at home. No more children born.
1891 They have moved to Herefordshire and both children have left home
1901 Still in Tring, Herts
Marriage;
Edward BENNETT
Mary Elizabeth PEARSON
March 1859
Berkhampstead 3a 359
Death;
Edward BENNETT
December 1902
Berkhampstead 3a 434
Age 65
Mary Elizabeth BENNETT
September 1908
Berkhampstead 3a 361
Age 71
So at least you now know he died in Hertfordshire!
Will try and find some of the others