There's an access panel on the ceiling right outside the head compartment door which has a small vertical tube through which the wires run up into the companionway instrument location. From there, another conduit runs forward (away from the power panel). That's where I got lost... I might be able to pull a new wire through using an existing wire, but it seems like there would be too many tight turns. What I was hoping for was an intermediate location somewhere in between that spot and the power panel.
While replacing my sanitation hose on Sunday, I think I found the missing link. The access panel inside the vanity, where the waste pumpout, vent hose, etc. are located, I discovered the wires from the companionway instruments, and it should be not too difficult to pull wires to this location. From there, it's an easy shot to the power panel, and then back to the stern and up to the helm. So I think I'm in good shape now.
--Michael