They make a 68-72 Skylark Model One Radio, and 68-72 Chevelle Retro Classic radio, but not vice versa. See my confusion? So my question is to anyone who has a Retrosound radio in their 1972 GS (or compatible) I want to order to order the Retrosound Retro Classic. So is the 68-72 Chevelle Retro Classic going to fit my 72 GS? Or do I need to buy the Model One version for the Skylark?