You need a bundle of ordinary woods, and read Way of woodworking Vol.1 to be able to fix the sofa!
I've read the book, and once I have time i'll try to see what I can do. It may be slightly annoying, but I might start a new save to work around it.
[Edit: It may sound dumb, but I never actually 'crafted'. I made it to 'Woodworking Vol.3', but never further. On my new save, I tried it, made it to 'Woodcrafting', and we're bing chillin' now.]