I have an SG which I believed to be dated from 1970/71, but can't confirm this. I know Gibson serial numbers are pretty unreliable from this time, but for what it's worth the number is 687171. The guitar has dot inlays from the first fret up, controls mounted on a half moon shaped black plate (2 vol, 2 tone and a selector switch), 2 pickups with black Gibson engraved plastic covers, no tremolo and is red in colour. Any help or advice as to where to look would be appreciated. Thanks.