Fuel tank replacement help

[crsavage1]

So I continued to remove the remaining floor. A few questions though, it seems the sub structure is a bit off.

1. It looks like someone tried to pour foam into the corners in the stern but am unclear why? There are big blobs of foam which I seriously doubt would provide any floatation so unsure why they would do that. Parts of the stringers weren’t raised so the floor was sort of floating.

2. I am unsure whether the tab I left in for the new floor is adequate enough to support the new floor? The material is questionable and pretty spongy so won’t that make the new floor spongy near the gunwales? If not, I am unsure of what the right way is to correct this situation? Cut the tab out to the edge? If I do that, doesn’t the liner sit on the floor? I am confused....

3. I added a picture of where it appears some of the stringers were cut out? I added a picture where I marked in red where it appears it is missing. Again, what is the best way to correct that?

4. Next step would seem to be grinding everything back out. A lot of the existing fiberglass looks bad and doesn’t seem it was laid up correctly. Is that the best step or do I need to be concerned about the tabbing for the new floor?

Any suggestions or advice welcome!