As for Siamese 'mix', having had many of them in my life, the way I could always tell if there was true Siamese in the lineage was to first stroke their fur, it feels coarser, 'different' than regular cat fur. They almost always keep their blue eyes, and they have a peculiar 'odor' on their skin too. Cat's fur usually doesn't smell at all, but somehow they have an odor that is all their own. not unpleasant, but not sweet-smelling either! This was always on the white kittens in a litter that developed points later.
