Recently I saw a (reverse) headstock photo of a Gibson guitar where the serial number was stamped in the traditional "horizontal" style, but the "Made in USA" was stamped "vertically". I've never seen that before, and it made me suspicious.
Can anyone verify that they've seen similar stampings on a legitimate Gibson guitar? That is, serial number and "Made in USA" stampings oriented at 90-degrees to one another. Here is another example that I just found: https://www.ebay.com/itm/Vintage-Gibson-ES-175-Guitar-/222766009457
Fyi, while researching this question, I discovered some helpful information concerning the headstock logos (see http://forum.gibson.com/index.php?/topic/74747-gbsons-headstock-logos/ for details). I thought that the "closed b" and "closed o" logo on my 1985 Howard Roberts went back much further into history, but this resource declares that '"pantograph" style, closed "b" and "o": 1969-1984'.
For related information, see What indicators enable consumers to identify counterfeit guitars?