New owner of 2363 - Rudder issue

I recently purchased 2363 and have been busily getting her back into shape.  One of my last projects for this year is the rudder.  It's useable as is but the fiberglass head is in tough shape: beat up, some cracks, difficult to swing the blade down, and it looks like there may be some extra holes drilled for unknown reasons.  I have a few questions, maybe one of you can help.  1) If I take all the fasteners out, will the head come apart along the seam so I can work on repairs?  2) Is the head solid fiberglass or is there a core that might be retaining water and freezing, causing the cracks? 3)  I see I can buy a new head from the factory but that's not in the budget right now.  Any idea where I might find a used one?
Big Dave