Same here
My 71 E29 has mahogany plywood covering what appears to be access areas on each side of the cabin. The cuts are about 8" wide and run the length of the cabin including the stb quarterberth. These cutouts are part of the liner attached to the cabin top. The V-berth has similar cut outs but are trimmed with the same type plywood so we have some storage area between the liner and hull. I've noticed pictures of later model 29's and they have a lot of wood inside. She has the pieces of plywood over the openings and the rest is all liner. No wood on the floors or cabin sides only the bulkheads. Makes it much easier to keep clean, don't have to worry about water stains, or wood associated problems.
Art M,
71 E29, #53