I have a beautiful Otwin Sonor, arch top, no cut-a-way, curved slash f-holes. Solid thick spruce top, strong straight grain. black curved oickguard, very narrow waist, and a very round lower body, harp shaped hammered metal tail piece. I got it on ebay for $193. It needed to go to my luthier to get the neck reset, and now it's a dream. Wonderful tone. Almost Maceffari. I'm guessing 1950's. I don't think I'd sell it, even if offered $1000. I believe that up to the installation of the Berlin Wall, these were high quality guitars, run by a venerable luthier family, and, unfortunately their reputation lessened in the 60's.