Oh Man, if that IS a 1996 radio, it uses a different style of connector. I can help you sort it out though, let me know man.
Radio is what, out of like a 96 C Class? i think all 96's used the same radio, i got diagrams around here somewhere. Let me know what you got and it'll probably be tomorrow night before I can dig into it. BUT you HAVE to have the connectors for the new radio, you got them? If not I think you're sunk.
Not sure about the antenna plugging in to the new style radio, don't know if there's an adapter you can get for that or what.

Gilly