The style in which the stocks were cut was probably a matter of personal or battalion preference. Some battalions, indeed divisions, reportedly did not permit cutting down of stocks; thus not much can be concluded from this. We have seen here on this forum a period photo of an aboriginal sniper with a non-scoped MkIII Ross showing a very similar "sporterization".

Without looking closely, probably the rifle is an assemblage as all but a very few are, even without the mixing and matching that doubtless went on during the three years or so that these rifles were used for training in Canadaicon during WWII.