Paul ---as Mabel has confirmed there appears to be one child alive with James Clifford Dickinson and his wife Annie on the 1939 Register. (On this register at the moment people born AFTER 1916 are blanked out for privacy reasons).
Of the 3 children identified as possibly born in Wales with a surname of Dickinson and a mother's maiden name of Thomas --- 2 were born prior to 1939.
A male in Neath Reg District in 1935
A female in Llanelly Reg Dist in 1936
However because the name of the child is blanked out it isn't known which one it is. On a balance of probability it will be male born in Neath Reg Dist, as that is where the family was living at that time.
I have checked for deaths prior to 1939 for both the male and the female - neither seems to have died. It is possible that the other child is still theirs but staying elsewhere OR belongs to another couple with the same combination of surnames.
The 3rd child I can see with a Dickinson/Thomas combination was a male born in 1946 in Dyfed Reg Dist -- again we don't know if this is their child as it is not in the area in which they were living in 1939.
The only thing you can do to check for certain if these 3 are James and Annie's children is to order the birth certs. If you order on line from GRO and request a PDF copy it will cost you £6 each.
Someone with the same first name, middle initial and surname as the male child born in 1935 married in South Glamorgan in 1990 -- but this seems a little late for someone born in 1935!
This couple are on the 2002 South Glamorgan Electoral Registers, but no age is shown.
An added complication is that we don't know when James moved from Wales to Andover. More children may have been born there. The move was clearly between 1939 and his death in 1949. His wife Annie moved back to Wales at some point where she died.
The only time you will find all members of a family together at an address is once they all reach voting age and are listed on Electoral Registers. You cannot guarantee this either - as a child may have left home.
You could try searching Public Family trees on Ancestry (subscription site) or on the free site Family Search -- HOWEVER you cannot always rely on the accuracy of other people's Family Trees.
You could try contacting a local Newspaper perhaps in the Neath area to see if they could publish an article saying that you would like to contact any descendents of James Clifford Dickinson born in 1906 who was a Postal worker in that area in at least the 1920s and 1930s.
I am sorry but at the moment I can't think of anything else you can do --- telephone directories only show the household head.
Maybe someone else will have a bright idea for you.
