I've been doing a bit more research on these two mystery men; I found
www.servicepub.com and to my delight found an incredibly knowledgeable and helpful man, who has put forward the following info on these two pictures.
(Re the younger, seated soldier)
The soldier is most definitely Canadian, although he is wearing the 5-button British Service Dress uniform. The formation patch on his sleeve will assist in further identifying the unit to which he belonged. The 5 Canadian Divisions each wore a different coloured rectangle. In addition, each rectangle then had one of four different shapes added to the top - circle, half-moon, triangle and square. These shapes were in three different colours for a total of 128 different possibilities. This soldier obviously has the half-moon on top of the rectangle. The problem now lies in the colours. The black & white photo doesn't confirm the colours - only that the rectangle and half-moon appear to be the same. This leaves us with three possibilities; 7th Battalion, 28th Bn or 46th Bn. My educated guess is the 46th which wore green formation patches as the photo doesn't look like it is either red or dark blue (both of which are much denser/darker in B&W photos. Based on the 46th Bn, this may help you in determining the subject. The 46th was disbanded after the war, as were all the battalions of the Canadian Expeditionary Force. Its Battle Honours are perpetuated by several different regiments, all of which are based in Saskatchewan where the 46th raised and recruited most of its strength.
http://www.saskd.ca/skd-hon.htm Unfortunately, the three possibilities all used a Maple Leaf motif for their cap badge and the photo is not clear enough to make out any detail. The same for the collar badges. The subject wears the standard "Canada" shoulder titles so nothing can be determined from this insignia.
Re the other picture, of the older standing man:
Photo no. 1 cannot be 47th as the Distinguishing Patch for the 47th has a very pronounced triangle on top of the rectangle. Photo No.2 appears to be the same man based on the shape of the chin. In the second photo the subject is wearing a Canadian Army Khaki Drill uniform (this pattern was limited to summer use and for wear in Canada only). A close look over the subject's left breast pocket reveals some campaign ribbons. It would follow that these are the ribbons earned for service in the First World War. He is not an officer - he is wearing a black tie and not a Khaki one - and he appears too old to be a Private. He has no Corporal's or Sergeant's stripes however, he may have a Warrant Officer 1st of 2nd Class badge of rank at the cuff of his sleeve. Chances are that he is a member of the Veteran's Guard of Canada. This was an organisation much like the British Home Guard. The VGC were used to guard Prisoner of War camps and other duties.
So I havent yet discovered who this man in the pictures was, but I know a lot more about other things than I did a week ago !
Re the info gained so far about the son of John James Stubbs, one Herbert Arthur Stubbs, I have found this from the Contalmaison war cemetery:
In Memory of
Private H A STUBBS
629370, 47th Bn., Canadian Infantry (Western Ontario Regiment)
who died age 23
on 25 October 1916
Son of John James and Jessie Stubbs, of 1266, Seventh Avenue West Vancouver, British Columbia.
Remembered with honour
SUNKEN ROAD CEMETERY, CONTALMAISON
War is a terrible thing ...
Thanks to all who have helped ... Lydart