My mast shoe did not have this but all my wires are looped before going through the deck. This has been effective since there are no signs of water intrusion on the wood compression post between the cabin sole and the deck. Note on boats that I looked at that were from the mid 90's showed signs of water on this post. I believe that all the water that deteriorated my post simply came in through the the chain locker. I believe that my all fiberglass/gel coat repair has addressed this issue.
Ellen sorry to not offer the quick fix and reassuring pat but as nifty has stated, it is fixable. Got to love these boats that are totally rebuildable. I share with you the patience the older boats require.
Keep us informed, -Scupp