I have a 1968 Sheraton that there's no way I'd sell it for less than $700 (actually, I wouldn't sell it at all. It doesn't have that goofy "by Gibson" headstock. I contacted Epiphone several years ago to find out more about it. Seems they can't even track the serial number. Back in '68 to '70 there was quite a bit of change going on in the production of their guitars and they didn't keep accurate records of the serial numbers and can't even tell if it was made in Kalamazoo or Korea. Their best guess is that it was probably one of the last ones made in the USA. The quality is the best I have seen in any guitar by any manufacturer.
Back in those days, people took pride in their workmanship. There was no cutting corners. I also had a 1960 ES330, a '68 ES345TDC, and a '69 LP Custom (black and gold). All were outstanding quality. Not like any made today.
What a shame. What a loss of pride and personal integrity. Sometimes I wish that I hadn't lived in the good old days so I wouldn't have to see such a degradation in quality in instruments in recent years.