C 420 Damage and advice?

[CRay45DB]

I have just picked up a used 420 racing bote. It's a 2004, great shape...or so I thought. When I got it home last night, I started doing my magic of turning it into a brand new boat again. As I got rid of the oxidation on the deck, I noticed 2 different colors. when I tapped on different areas, very different sounds compared to the side. pics will show you the discoloration. The boat is in my garage, so I climbed in under the deck and took a picture from below. Based on the form of the variance, and the obvious of what you see, Houston, I think we might have problem. But how much of a problem,? Would be greatly interested in your thoughts.

Thanks

 

[mickyryan]

looks like you removed most of the gelcote, one option would be to re gelcote most likely it was always thin because well its a race boat

 

[CRay45DB]

No, just got the boat yesterday. Didn't remove any gel. Take a look at the rest of the pics, there are 9. I should probably get rid of the top side ones. It will make more sense.