I took a CP non-stop flight from YYZ to CUN in March 1996, operated by a DC-10. I got to sit in the Club Empress class for something like $100-150 more than the regular economy ticket. If I'm not mistaken, the tickets were sold by Canadian Holidays but I got full AAdvantage miles for the flghts.
It was a nice treat sitting in a big old DC-10 in J class to CUN