Hi Jojo, if Diageo didn't get this brand then it's possibly still with Chivas as I know that Chivas bottled the brand in Scotland back in the 70's and 80's. It's very possible that they leased the brand to the Quebec Liquor Board to allow them to bottle it in Canada from whisky shipped by Chivas.
This happened with a number of companies and Liquor Boards in the 70's and 80's but seemed to stop in the late 80's. I know that the likes of the LCBO were buying new blend [i.e. new malt and grain, blended and then matured in Scotland] then shipped and bottled under their own brands.