I cannot prove it, but I would bet money that it is Chinese and not Japanese. There are many grinders out there with SGS-H618B on them, but not that "brand" name. All are from companies that sell mostly Chinese machines. Still, from the pics it looks like new. Might be worth it for that price. Simple manual machine. Take the table off and look for wear or other issues. Tables usually lift right off surface grinders, though there may be a cable or or other attachment for traversing the table. It should be easy to disconnect. Look at the ways, even if the machine is new. If there are no visible issues with it, and it moves smoothly, it will probably be just fine for a hobby machinist shop. Check the spindle as well, the heart of the grinder, for anything other than dead smooth when turning it. Also check for play in the spindle. Run it under power after checking the spindle by hand turning it. The chuck appears to be 6x12".
