Hi,
I think you will need to buy a copy of the birth certificate.
FreeBMD has this registration but too many differences:
Aubrey J Chapman DecQ 1920 Salisbury 5a 295 (mother Burt)
Possible marriage registration:
Wilfred G Chapman SepQ 1915 Salisbury 5a 479
Bride: Ethel M Burt
Can't see an Aubrey Walker Chapman.

Just found a birth for an Aubrey W Chapman DecQ 1912 in Warwickshire.

Nanny Jan