This is a vintage marking gauge from the 1800s. The only markings on it are C.A.S. It’s made of rosewood and brass and has wonderful historic patina. The sliding brass pieces are ornate and work great. The single nib is in near perfect shape and would mark very very well as it is. The mortise side nibs and a little worn down clearly showing this tool was used primarily for mortise and tenon joinery. It’s a fantastic piece of history, showing normal wear for a tool that was used in the hands of a skilled craftsman over a century ago. The gauge is strong and durable still to this day and the brass looks good against the rosewood grain. You could display this tool because it looks so good, but and even better option would be to put it to work like it was intended.