I'll say you can try soldering, etc and that should get you back to being connected. Only big concern is the shielding around the wires that keeps stray signals from other things such as the trolling motor from doing bad things to your signal. If it is not intact it is impossible to put back as it originally was.
You should call Marine Repair Center in Springfield, they are excellent about telling you the straight skinny. And not to just sell you something.