Unfortunately I did not take any photos of my C-30 keel re-set but I can tell you with 100% certainty there was NO WHERE near 1" of solid glass in my keel stub.
Here are a few pictures of a Pearson 26 keel that snapped off so folks will get and understand why plywood should NOT be in a keel joint.
These pictures are NOT a C-30 but simply to show the construction technique. The fiberglass laminates on my C-30 were "slightly" more robust, but not a lot more, and certainly no where near an an inch! the bottom skin on my C-30 was roughly 3/8 of an inch thick if that...
If you have plywood in your keel stub I say replace it! Remember though what you paid for my advice..
The Sinking Keel Bolts:
The Bilge Side:
The Keel Side: