Just to answer your original query, I don't think the Royal Navy man is the same person as 'your' William. On the Navy record the man was born in Willesden Green and prior to joining the Navy in July 1919 he had previously been a steward in the Merchant Navy. In the 1939 Register there's a Horace W Cleaver date of birth 20 Jan 1900 single, a caterer (snack bar) living at 29 Vardens Rd Clapham, so he may possibly be the Navy man. There's a Horace William Cleaver in the 1921 Census living with an Alice Beatrice and Joseph in London. I haven't paid to get more details. However Horace William Cleaver born Q1 1900 to Joseph and Kate Cleaver in Hackney which is the opposite side of London to Willesden Green. In the 1901 Census Horace William is living with parents Joseph and Kate Cleaver at 27 Englefield Rd Hackney, and in 1911 he's still with his parents (married 12 years) at 7 Wellington Road Hackney along with 4 sisters one of who is named Alice B Cleaver. William died in Bermondsey in 1940 aged 40. That all points away from your William being the Navy man, who seems more likely to have been Horace.