Hi,
Yes, I think so. On our 1984 E 30+, I replaced our VHFradio and the stereo in the location that I think you are referring to. I had to remove the teak moulding directly above/in front of the nav station going side to side above the hanging locker there--only a couple of screws. Then I removed the four screws in the teak panel that angles below the port there (I'm not at the boat and am trying to remember exact position
). With those screws removed, I could pull that teak panel forward giving me access to the back of the VHF radio, stereo, etc. By fishing with a coat hanger, you can probably get the wire you're looking for. If not, you could try removing the electrical plug above the nav station and fishing a wire down through that smaller opening. Failing that, on our boat there is a small opening port below the cushion in the quarterberth in front of the square battery compartment. By opening that port, you can access the hull (albeit awkwardly) below the nav station which may help you.
Good luck! Let us know if you're able to retrieve it!
Frank