It does look great
Claude, My wife and I just finished the exact same project to our "new" 1985 O28. It really does look great, but I hope you are ready to invest a lot of time and hard work to complete the project. We removed all of the liner from the whole boat. Then you have to wire brush all of the foam backing off of the inside of the hull. If you get past this the really hard part is over. We did a lot more which I will be posting soon when I get some pictures ready for the site, but back to the wood ceiling. I purchased 3 10'x8"x5/4 Ash boards. Surface both sides smooth to finish as close to 1-1/4"thick as possible. Be sure to do this all at once so that all the boards are the same thickness. Next get help to saw 5/16" thick strips off of the boards. I think I used 30 or 35 strips but I can't remember for sure. Next surface each of the strips to 1/4" thickness. Set up a router table to cut a 1/8" chamfer on both edges of the the best side of the strip. Sand the finished side smooth (100 then 220 paper) and begin to cut to length. Measurement here is critical so measure twice and cut once. Be sure to allow for the curvature of the hull. I used 3/8" thick by 2-1/2" wide cover boards screwed into the bulkhead to cover up the small gap at the end of the strips. These all had to be hand fitted on the boat. A hacksaw with a fine blade and a sanding board works well for accuracy here. We covered all of the space above the shelf up to the deck in the main salon, the space in the quarterberth from the nav station all the way aft, and went crazy and puzzled together the space at the back of the shelves of the galley. I used 4200 as the adhesive and scrap styrofoam as bracing material to squash the strips up tight to the hull while they dried. If I were to do it again I would put a little more prep into the clamping system maybe using small screwjacks against 2x2's braced on the other side of the hull. A light sanding and 2 coats of satin varnish later and you have gone from a sailboat to a yacht. It really is alot of work, but I can't describe the satisfacton when it's all finished. If you can't do the wood prep yourself, this might turn out to be somewhat expensive to have done at a mill. 1-1/4" pine lattace strips might be a way to go as an alternative. Also we used off-white vynal over 1/4" foam glued to the hull sides in the V berth which would also work for the rest of the hull if the wood project sounds to tough. Good Luck - I hope yours comes out as well as mine did. PM