Mothers forename was Martha Jane.
I don't know of a 1939 register, what is this please?
Yes, the couple that you are referring are Joseph and Martha Jane, married in 1901. I agree that it seems unlikely that they would have a child in 1929. This is the reason that I suspect that the child was not theirs but came from somewhere within the family. There were two other children Ann Jane b1904 and Thomas Cecil b1909. Whether either of these two had an illegitimate child is a possibility I suppose.The child born 1919 is my father.