The Mauser, Oberndorf commercial serial number 51354 dates the action to 1912, thanks Jon Speed.
By mid-1916 German ordnance had finally figured out how to convert the infantry rifle Gewehr 98 into the scoped Scharfschützengewehr 98. Now the stop-gap sporting rifles were withdrawn from the frontlines and put into storage. As riflescopes were in short supply, the scopes were removed from the retired sporters and mounted on the regulation sniper rifles. So not one of the military accepted sporters retains it's original scope. IMHO the Parker-Hale base was added post-WW2, after the rifle was finally liberated in 1945, to mount a scope. Also, the "ideal gun" marking appears spurious to me, as it is applied with single letter stamps. I don't know Canadian gun registration laws, but German law now requires every gun to be marked with a maker's name or a "known" trademark. Many old noname "trade" guns are crudely ascribed now to a "maker" in this way.
As your rifle was accepted for military service, see the eagle stamp, there should have been a military registration number with either a D or Z prefix stamped into the right side of the buttstock. If a D prefix number, there should be the traces of four pinholes also. Here a warning plate was applied, reading "Nur für Patrone 88" = only for cartridge M88/8x57I.