I'm following up on my own post. I have done a bit more research on this spoon. The retailer was C. Oskamp who were located in Cincinnati. Duhme & Co. were a large manufatuer (as well as retailer) in Cincy during this period. I've searched my resource material and can't find that Duhme ever used this mark, but I'm guessing that this may be their work. Any thoughts? Thanks!