Super water logged Eclipse

I have two 12' Blue original fiberglass Eclipses. One is perfect so I know how light it should be.
The other I got for 50 bucks and it weighs a ton from being waterlogged.
The nose is cracked badly vertically and I have set it nose down for a week and some water came out.
Just drilled some holes in the rear where there were dings and set it tail down for a couple days now. Some water came out initially, not much, seems to have stopped.

I am thinking of cutting a 12 X 20 patch out of the top deck in front to expose the foam in a big way.
In the rear I could cut a smalll patch away behing the rudder.
then fill in any foam I cut and fiberglass the patches back when its dries.

Has anyone tried something like this? I have done some big fiberglass work on boats so I'm not scared but any advice on do's and don'ts is appreciated. Any spots I should avoid cutting near besides where the cables run and the pedal area?

Thanks in advance, BF