Try this. If it works, great. If not, them you're no worse off than you are now.
1. Pull the old wire through the bottom of the pulpit. You already have the pulpit unbolted, so it should be easy. Pulling is far easier than pushing!
2. Pull the ground wire from a length of stiff house wire (single strand 10 or 12 gauge). It's uncovered, so you won't have to strip off the plastic coating.
3. Push it through the hole where the bow light wire should be toward the base of the pulpit. It's stiff enough to push past the elbow.
4. When it exits the bottom of the pulpit, put a small hook on the end with a pair of needle nose pliers.
5. Clip the old wire, but leave enough to attach a new length of wire to it. That is, don't clip it flush with the deck!! Don't do this step until you complete step 3, or you could be screwed.
6. Attach the new wire to the old one using proper splicing methods.
7. Strip off about an inch of insulation from the other end of the positive and negative strands of the new wire and join them making a sort of loop. Hook the loop over the hook in the stiff wire and neatly wrap the joint with duct tape for strength
7. Pull through from the bow light end.
Sabre 38 "Victoria"