This Gibson SG was built in 1970, 1971, or 1972 (the serial numbers are not exact from this period). We believe it started life as a SG I, which was a single pickup guitar. It appears that it was modified and routed to accept 3 humbuckers like a SG Custom, with a custom pickguard made for new electronics to be used.
The guitar has been setup and plays very well! We are currently (October 21, 2017) replacing the bridge with a nicer unit and will be refurbishing the electronics also. This is a great way to get a true Vintage SG for a fraction of the price of a Custom!