Kenyon mast?
Did all the H37Cs have the same mast I wonder? My 1979 has the Kenyon mast and I just rewired it this Spring. The wiring is behind the sail track which slides out the bottom of the mast. And the wiring is heavy and thus must be anchored with cable clamps, one every ten feet or so I think. So there is no way to pull it through without cutting those ties.The cover from the bottom of the mast to just behind the boom attachment is some kind of very hard plastic. In an attempt to stop water from coming down the track a previous owner had filled about six inches of that with a caulk. That section would not slide out until I cut the piece out that was binding. After that the metal track, in two sections on mine, slid right out without a problem. But I had soaked it a few days before with WD-40.Once it was open I removed all the old wire. There was two wire cable to the anchor light on top, three wire cable to the combination steaming light/deck light on the front of the mast, and the coax for the VHF antenna. I ran all new Ancor wire, three wire cable to the top this time for a new combination anchor/running light. And new coax. I retied inside the channel with nylon wire ties, the kind that you can rivet in place. All of this thanks to Tom Hadoulias who guided me through the steps but could not tell me why that #*!$% lower track would not slide out.

I can not think of any way you could do this job without having the mast horizontal. The track cannot slide out the top. Good luck.