Bob,
It is my impression that the "Mexico" was their top of the line, with a cassette deck builtin. Then the "GrandPrix" which was a AM/FM with automatic tuning bar on the radio, then the "Europa Stereo", then the "Europa" mono AM/FM . There were differences between the bands for US and Euro models (Euro models could have SW short wave bands). I hope that helps. I purchased a Europa Stereo, since I was afraid of the expense of the Gran Prix auto tuning failing.