To sum up:
1881 Census, we have Wilfrid, born in Eccles around 1880. James and Mary Johnson are his parents living at Booths Hall Avenue in Worsley. Also listed are brothers Percy C (age 6), Harold M (4), and Leonard C T (3 weeks or months).
1891 Census has Wilfrid at prep school in Sedbergh. This census doesnt tell us much else. Think father died previous year.
1901 Census has no mention of Wilfrid, but Percy (26), Harold W? (24), Leonard C (20) living with Mary. Northfield and Bury Old Road are mentioned but the address is a bit confusing.
1911 Census has Harold Marsland Johnson living with wife and two children, Alfred Clarkson (7) and Betty Clarkson (3). They are at The Old Tannery Tynnes Cheshire. No idea where this is but the district is Bucklow, not far from where I live.
There is a military record of a Percy Clarkson Johnson of the Manchester Regiment getting killed in action on 15 May 1915, and there is a probate record stating death at Dardenelles which ties in with what Baz says. However , he is listed as being from Namilongwi Pemba, Northern Rhodesia.
James (the father) is listed in the 1881 census as being a cotton spinner employing 78 people. However there is a probate entry saying James Clarkson Johnson died on 28 March 1890 as an ironmaster at Bradford Iron Works. Brother is listed as John Thewlis Johnson, hence why I think he is related to this bunch and is the same person. Estate valued at £41,531,9s,8d, btw. That would have paid for the camera.
Finally, Harold Marsland Johnson turns up dead in 1949 with Robert Alfred Clarkson named in probate. One of the same name crops up in the UK patent applications as applying for a patent in 1930 on behalf of the Bradford Iron Works:
http://patent.ipexl.com/GB/GB347045.html
Phew.
Shame the globetrotting exploits of Wilfrid prevent him from appearing in the UK records, though.