On a side note... Does the wiring harness that is in the back of the busted headunit come out? If it's some sort of name brand, they typically will unplug from the back of the headunit. You could go and find a replacement from the same brand and possibly be able just to plug in to that old plug.
JVC uses the same "mini plug" on a lot of their headunits. When I drowned my $200 unit, I replaced it with the cheap JVC I posted above. I went that route for a few reasons... First is that it was cheap... And second was that it was plug and play! I didn't need to redo any of my wiring at all to make it work.