The brother Alice is living with in 1939 in Edward Gibson.
Have looked into the 1939 register which puts my grandad at the age of 5 living in Abingdon road Berkshire. The strange thing is he was written down as Peter Morton but above it has been changed to blanchford. Surely this would mean that Montague would have known my grandad at at least 5. Grandad is living with a Frank cotmarr born 1878, Ernest j songshaw, Sylvia songshaw born 1909 and 1 other person that says officially closed.
I cant place Doris in the 1939 register there are 4 Doris Morton's that fit but they are at places that she has no connections with. I found Montague in this 1939 register also but he is living with his wife in London.