First order of business - Stabilize the wood.
I used the same method I employed with my other Defender. Saturate the wood with a penetrating epoxy, wipe off the excess and clamp down using blocks of wood wrapped in plastic bags. I made sure the epoxy got into all the voids and under the delaminated layers. I used Abatron LiquidWood which has worked well on several other projects of mine.
Nice thing about using the school shop - lots of clamps!
A day later everything is solid. No flaking or loose wood. Not pretty yet but the damage has been stopped.
Filling in the wood was done using another two part epoxy. This time I used HF Staples Epoxy Wood Rebuilder. It has the color and consistency of peanut butter when mixed. It's easy to apply and sand, it's now my favorite wood epoxy.
There were some big chunks of wood missing.
Everything sanded down nicely and was ready for paint.