OK, I am not certain whether I have cracked this or whether I have found a huge number of coincidences and I have jumped to conclusions...........
HWS and Lilian Hilda Slinger had a daughter in 1936. If my theory is correct, this daughter is now deceased, but I would prefer to err on the side of caution! This daughter has a rather unusual first name beginning with M, followed by a middle name also beginning with M. Looking for marriages for her from about 1956, I found quite a few but none with the surname of Slinger.
I then decided to do the same search for the daughter born in 1933 (initials JW) and cross reference the surnames. There was a common surname - Drummond.
Deciding to push my luck, I looked to see if I could see any trace of Lilian Hilda with the surname Drummond - and yes. There was a probate record for a Lilian Hilda Drummond, dying in 1970 and probate in 1971. By pure luck, I noticed that there was another death for a Drummond at the same address as Lilian - one Rex Drummond.
There is a Rex Drummond who appears in the London Gazette several times due to bankruptcy proceedings, with address given as The Glade, Stoneleigh, Epsom. The 1938 electoral roll for Epsom show Rex Drummond and Lilian Hilda Drummond at 60 The Glade, Stoneleigh, Epsom.
Is HWS Slinger AKA Rex Drummond? Or have I put 2 and 2 together and ended up with 9 million?
