Converting to full infusion style. Drilled lots o' rivets out. Moving the rotation arm down, using the halyard sheave in the new mast base. Pulled the old halyard block and rotation blocks off the front beam. Have to mock things up to see where to reattach the cleats for the downhaul.

So, I went with Todd's advice - 4200. Hopefully I'll have moved to a new F-20 before I need to pull it apart! ;-) Sealed up the two bolt holes with silicon.