Rare Yamaha SA-5 hollowbody.

Based on serial stamp, it appears to be among first 100 built at Nippon Gakki circa 1966-67.

Little documentation on SA-5 exists as these guitars were likely only sold in Japan and short-lived before the SA-30/50 were released.

Notes on condition (shown in photos):

• Close-up shows holes where pick guard was originally attached (pickguard is missing)
• The “zero” fret is original design of guitar, not a modification
• Grover tuners are after-market. They do not align with pilot holes of original tuners.
• To my ears, the Balancer knob functions as pickup selector, not what is indicated by circuit diagram. This may be due to custom wiring or differing specs found in the later models.
  
  Additional pictures by request.
  
  Thanks for looking.