Hello
As this was all so long ago, I'm presuming I've missed the boat but I too am researching this line
I have Reuben in the 1891, 1901 & 1911 but cannot find him in the 1881 or earlier
Not knowing when he arrived in the UK, it could be of course that he wasn't in the UK then
By the births of the children, it appears they lived in Gloucestershire twice and the East End in for the main part which would be fairly normal being a Jewish family
I have "some" information on them, not a lot but you're welcome to what I have if it would help you
Cheers