Ulmia Ott No 732 Scraper Burnisher -- Made In Germany
If you struggle with sharpening card scrapers, this tool will help. The Ulmia scraper burnisher has a hardened steel wheel that comes in contact with the scraper's edge at just the right angle to turn a proper hook. In fact, it is so effective that it is too easy to create a hook that is too big. Only a light touch is needed.
These were once sold in the U.S., but are now hard to find. This example includes the original box and paperwork.