Hello Joy,
You certainly have a difficult task.
Grasping at straws I'm afraid ...
1. I notice the following entry on the CWGC (Commonwealth War Graves Commission) site.
Name: LANE
(no given names or initials listed)Nationality: United Kingdom
Rank: Sailor
Regiment/Service: Merchant Navy
Unit Text: S.S. Maas (Netherlands)
Date of Death: 11/09/1940
Casualty Type: Commonwealth War Dead
Grave/Memorial Reference: Panel 131
Memorial: Tower Hill Memorial
The site advises that "The Tower Hill Memorial commemorates men and women of the Merchant Navy and Fishing Fleets who died in both World Wars and who have no known grave. It stands on the south side of the garden of Trinity Square, London, close to The Tower of London. The Memorial Register may be consulted at Trinity House Corporation, Trinity Square (Cooper's Row entrance), Tower Hill, London EC3 N4DH, which will be found behind the Memorial. Tel: 020 7481 6900."
Googling finds the following site:
http://www.battleships-cruisers.co.uk/ww2_u-boats.htmwhich indicates that the SS Maas in Convoy OA210 was sunk by UBoat 28 in the Atlantic Ocean.
2. I wonder whether you have consulted the NSW Post Office Directories for ARMSTRONGs (or even LANEs) in Halley St, Five Dock in the 1900s? They are often available in State Libraries.
3. It is interesting that there is an ARMSTRONG-LANE marriage in NSW (posted earlier by regross) - 1912 in Ashfield (not far from - virtually adjacent to - Five Dock).
Perhaps if you are in funds it might be worth getting a transcription of the marriage certificate just in case there are any clues ... Or perhaps even to eliminate these people.
Best of luck,
JAP