Thank you for taking the time to look at this Matthew.
Leonard's date of birth was established as 11.03.1898 from the 1939 Register, where he was resident at Wray House, Chelsea. The location was corroborated from first hand family knowledge. From there his birth certificate was obtained, giving details of his mother and father, George and Annie Day. Location and George King's occupation also confirmed from first hand family knowledge.
Additional sources for Leonard's father were the certificates of marriage to Amy Ward and Ruth Day. Census records for 1901 and 1911 give mother's and father's names and again agree with family knowledge of profession and location. I have been able to confirm the names of some of his siblings via the descendants of one of his sisters, so I believe this is the correct family. However, I haven't yet been able to find a marriage record for George and Annie Day, or a birth record for Annie.
We were told by Leonard's pension company that he died on 10 July 1979 at 81 years 8 months old. This is a discrepancy of 4 months, but could have been a transcription error or misundertanding. Subsequently I made contact with the family of Leonard's second marriage and details of his death location obtained. Probate records agree with the date and location of death but I am unable to account for the birth date of 28 February 1897 and haven't been able to find a birth record for either a Leonard King or Day that would be a good match.
I hope that is of some help. And my thanks once again.