I motored Tally Ho home from about 10 miles out on Lake Michigan when my forestay chain plate broke. I had 1 halyard available and I wrapped the anchor chain around the furler drum to help hold the whole rig from falling backwards. You should certainly be able to keep the mast in place with a halyard or 2 tied off up front and tightened on a winch.
Good luck on the project. I have new rigging being made for Tally Ho (I went swaged on both ends) and I have ordered a new Harkin MKIV Unit1. The rigger is going to assemble it in his shop (get all of the foil sections cut to length, etc), but then I will install the rigging when I get back for the summer, including re-assembling the furler at the marina. The ONLY thing I am nervous about is the furler. But with a few helpers, I am sure I can get it on the mast, get the mast stepped, and all the rigging secured.
New sheaves for the mast head, new VHF cable, new antenna, new anchor light, new foredeck/steaming light and some mast exit plates should finish off the project. Oh…and some new halyards since my old CDI furler didn’t use a rope halyard.. need to add a new one.
I will have about $5 boat bucks (maybe a bit more) to get fresh rigging on Tally Ho.
Greg