This photo shows the headliner where the mast support beam and starboard main bulkhead fit into their channels. The wires hanging down are the OEM mast wires. They came down through the hole under the mast step and back up into another hole (1) in the headliner. They then went to the hanging locker. I cut a groove in the top of the mast support beam and ran the wires to it's starboard end. There I cut a hole in the edge of the moulded channel (2) of the headliner. I ran the wires down to the hanging locker (3) through the forward side of the channel moulding that holds the main bulkhead in place.
For a view that shows the hole I cut in the headliner molding see the "Interior Looking Aft" photo.