Sally, if you want to pursue the family that I suggested in reply #29, I'd suggest you try to trace forwards as many of the children as you can, just in case any of them ended up in Nottingham or can be connected with Harry Daniel Jackson in any other way after 1901.
An outlay of £6.00 for a pdf copy of Daniel's birth registration would allow you to cross-check his birthday with that given in the 1939 register, even though the year is different. The registration was in the 4th quarter of the year, which would be consistent with a birthday in late September. Just a suggestion.