I'm no expert in the field whatsoever, apart from having owned a number of newer Gibson SG Standards. A couple of weeks ago I stumbled across a 1977 left handed Gibson SG Standard and the guitar absolutely blew me away. It's all original except for the tuners that seem to be period correct Gibson ones instead of the Schallers I think they came with (you can see the old screw holes). The build quality and the wood is on a completely different level and the Tarbacks are the best humbuckers I've played. Very good tone and separation. The neck is slimmer than the newer SG:s, but it's very comfortable to play (I've got pretty big hands, not Donald Trump-style, but still). If you can get your hands on one of these you shouldn't hesitate.