Thanks for the pictures. It looks like they just epoxied the the wood straight to the inside of the shell. Maybe using something with some
fiberglass filler in it. Good to know. I was afraid that you'd need to
fiberglass over the wood. The way its shown in the pictures looks like it will add to the rigidity of the wall, which seems like a good thing. I would assume once you've done the tabbing you can then screw any cabinets right into the wood from the side with wood screws. The wood here looks like pine, but I'll probably use a hardwood just because. 2x1's it looks like.