Gut Check for repacing standing rigging.

[Bubba the Pirate]

I will not likely be stepping the mast and getting into this until late Summer, maybe early Spring 2012, but here is my current plan to replace standing rigging and replace current chainplates with external ones a la Fred Bickum's Fenix.  http://www.sbastro.com/FeNIX/Projects/Rigging.htm.   Fred's main site is: http://www.sbastro.com/FeNIX/mainFrameSet.htm  Also DaveC on Alaina followed Fred's lead. 

Currently, the boat is on the hard, the mast is down and across town in the marina's mast rack.  Cape Dory chainplates are actually bronze fittings bolted through the deck to a section of mild steel angle iron that has large steel 'J's' or fishhooks f'glassed to the inside of the hull.  http://www.capedory.org/board/viewtopic.php?t=25957

I would like to cut out the 'J' hooks while I'm working on the interior.  Then they would also be out of the way when I drill holes for the external chainplates. 

However, the trick is this.  I'm going to need to re-attach the old rigging in order to measure, cut and install the new chainplates and the new rigging.  My plan is to fabricate metal backing plates to reattach the chainplate fittintgs to thru the deck.  When the marina puts the mast back up, these will hold the mast up and steady it as I climb the mast.  The boat is in a protected spot under a bluff that protects it from the prevailing wind.  I can use halyards and other line to give extra support to the mast.  An old picture of where the boat sits: https://picasaweb.google.com/lh/photo/lbCb4jVeu0nLaL5kiBa5Og?feat=directlink

What am I missing?  Any thoughts or comments are welcome. 

Thanks,
Todd