Rewiring the Mast without Unstepping

[Peel]

As the new owner of a 1985 Contrast 33, I'm slowly working my way through the previous owner's deferred maintenance and doing upgrades along the way. Now that the weather is starting to look a bit nicer, I'm getting ready to transition from interior projects to exterior ones. The biggest one I currently have is rewiring the mast. The anchor light doesn't work (though this one may just be a burned out bulb - won't know until I get to the top on the mast). But the steaming light has a short in it somewhere - switching it on throws the breaker in about 4 seconds. I'd also like to add deck lights to the spreaders. The price I was quoted from a local rigging shop to unstep the mast for me to do the work then re-step was more than I have in my budget.

Has anyone rewired a mast in situ? I estimate the mast to be about 55 feet from the keel to masthead. I don't know for sure, but am assuming, given its age, it does not have a conduit inside. I'm fairly comfortable working aloft, so no real concerns there.

If you have any tips/techniques for rerunning the wires, or obsticles to look out for I'd appreciate hearing from you in the comments.

-Pete