Replacing transom, should I beef up inner skin?

[TMala]

I am replacing the transom on a 1969 20ft SF. I am replacing it from the outside in. I have taken everything out to the inner skin and the inner skin has a lot less material than I thought it would, some spots are completely showing through, some have unsaturated woven. It appears to be original. I would compare it to an un tightened drum, is that normal?

I'm trying to figure out if I have enough room to add to the inner skin from the outside but also contemplating replacing the transom from the outside like planned, then cutting out the fish boxes so I can then add a layer or two of 1708 to the inside of the transom as well. This is my first transom replacement so not sure if what i'm seeing here of the inner skin is about normal or needs a little help.

Thank in advance for any advice. I will try and post some pictures to show how its looking.