Have just had a look on 1939 register, lots of leach names in St Thomas area. If you know the name of an older sibling, who is now deceased, or mothers name, you might find them. Easier to send for the birth certificate, and then work on the register from there, as you would get an address on the certificate, and parents names, which would also get you on the 1911 census, depending on their age. Possibly. good luck.