I acquired this guitar in 1989. Based on the serial number and known configurations, I believe it is a 1986 Studio Standard. But... it has been modifed after market as LP Custom-style inlays have been added. Gibson alerted me to this possibility and sure enough, you can see the modification on the 12th fret - the dot inlays have been filled in. Its a very good job as I've never noticed in the 30 years I've owned it. Does the inlay add to the value? Is this definitely a "Studio Standard"?