This is a now-discontinued CSG-631 made by Matsumoku, sold in the 1960s by Columbia! It's a rare item with a low production number. 【Item Condition】 The logo and model number have faded, and there are scratches due to aging, but there is no damage that would hinder playing. The tuning pegs feel stiff. Output has been confirmed through an amplifier, but it could not be confirmed from the front pickup. Sound output from the rear pickup, as well as changes in volume and tone, have been confirmed. Switch changes are also OK! Please be aware that there may be some crackling. This is the only one currently available, so please consider it. Please check the photos carefully and purchase with the understanding that this is a used item.