I bought a package of tortillas today at a combination Mexican restaurant and tortilleria called "Can-I-Mex". While they do contain preservatives, they were the most authentic tasting ones I have ever found outside of Mexico.
"Can-I-Mex" is not in Toronto, however, but in Hamilton, on James Street North. All Mexican food lovers who find themselves in the vicinity should definitely try them.
...sounds like you know more about it than I would, check out the front table at Perolas in Kensington, they have a bunch of different ones available, maybe one would suit you...or, it looks as though Davedigger will be turning them out soon!