question about Alpine CD Changers.

I have a NIB Alpine 1203 CD Changer controller and 5952Z changer (also NIB ). I bought them new when they were new I can't remember how many years ago. Looking to install it in a 69 New Yorker that I'm not willing to modify the dash in. I know that the aftermarket makes radio's that fit in the stock opening but I don't want to remove the factory radio for aesthetics.
My big question is will a later model CD changer work in place of the 5952Z because it won't be able to play MP3 and burned discs. Are the multi pin plugs proprietary between the Alpine models?