Hi,
Still cannot find William Armstrong in the 1911 census.
My next step is to try and confirm the children of William and Florence and order a couple of birth certificates to confirm address.
I am aware of :

John Norman Kneale Armstrong b. 1904
Ivy May Armstrong b. 1906
William Arthur Armstrong b. 1908 (Lonan -- data from ManxBMD.Com)

I also believe further children were :
Thomas Douglas Armstrong b. 1911 (Marown --data from ManxBMD.Com)
Leslie Clifford Armstrong b. 1914 (Marown -- data from ManxBMD.Com)

Are you aware of the additional children ?
Would appreciate if you could confirm as I will then order the last two birth certificates.

Thx