Hi there,
The link does appear plausible, at least.
From his NAA records, "Celestine Houlgrave", state children's department, Adelaide, was Norman's NOK on enlistment - unclear why, as both his parents appear to be still living in 1920. He also had scarring "left face and right leg through burns".
These bits of information would be useful:
1. birthdate for Henry Wilson (even with wrong year, right day/month would be a very strong bit of evidence).
2. any physical description/picture for Henry indicating whether or not he had the same identifying features as Norman.
There seems to have been something interesting going on with this family at any rate:
son "John Edward Norgren" died in WWI - his next of kin was mother of Broken Hill, via a married sister.
1921 - marriage of a daughter of "Mr and Mrs Edward Norgren"
http://trove.nla.gov.au/ndp/del/article/35252743?searchTerm=%22Mrs%20Norgren%22%20%22broken%20hill%22&searchLimits=1925 - engagement notice of Tracey Norgren, second son of "Mrs W Neale":
http://trove.nla.gov.au/ndp/del/article/87510489?searchTerm=%22Norgren%22%20%22broken%20hill%22&searchLimits=l-decade=192So there were definitely Norgren relatives in NSW - and despite the fact that "Johan Norgren" doesn't appear to have died until 1937 in SA, Elizabeth Hammond may have been going by another name over in NSW (cannot find a marriage to a Mr Neale, either).
I would suggest you look to see if you can find what happened to Elizabeth, and also any witnesses at the marriage of Henry Wilson who might be connected to the Norgren family in NSW. He might have kept in touch or got back in touch later with some of the family, even if he was trying to keep off the radar re: his short-lived Navy service.