I would recommend sanding the entire room down to clean wood. Start with a side grinder with a 5” disc to get to good clean wood. You may have to experiment with different grit disc. 50 or 60 grit is a good choice to start with. Then take a orbital or palm sander and sand smooth with 60 or 80 grit disc. Perma Chinks Life Line Interior stain is what I would recommend for a finish. Inside you can go as light as you wish since there is minimal UV to deal with. Also applying a couple of coats of Acrylic Clear Coat is recommended to put a good shell over the stain to protect it. You can get everything you need from Timeless Wood Care Products at www.timelesswoodcare.com or call 800-564-2987 and Dave would be happy to help you with other questions.