If your boat has the original Kenyon spar system, there probably is a multi-sheave box at the top with two "wing" halyard sheaves on either side of the forestay. On the outside facing forward is a polished (well, it was polished when new) SS cage to keep these halyards from unduly chafing on the sheave boxes.
I wonder where the original halyards (or tag lines) went? Oh well, decades have come and gone.
Other owners should have strategies for getting a new set of halyards down the inside and out of the exit slots above the boom. OTOH, I would bet that the mast does have all of the slots for those missing internal halyards. Hope so anyway.
You will also have add turning blocks at the base. There may or may not be unused sheaves in your housetop "organizer" leading back to a winch. Plan B: You could alternatively install a new winch for this on a new base on the spar. There are good arguments for doing it that way.