I'll answer part of your question. There are probably 2 conduits. One goes to the masthead and one to the lower spreaders. You may be able to see the conduits by looking through the halyard
exits. Sometimes the conduits are held in place by rivets, so if you find some rivets with no apparent use, they may be holding the conduits in place.
This may be easier to ask the Catalina
owners group. Surely someone there can help.
Finally, if you go to the website of your mast manufacturer you may be able to ask them where the conduits are located on your mast.