If it has an extended fingerboard it is NOT a 1968 F12, I had a '67 F12, the finger board was not extended, it had an unbound headstock with block letter GIBSON.
Those 70's F12s did not pack very much credentials ! I"m at the library, so I don't have my GIBSON ser. no. info with me, when I get home I"ll check the no. you gave against my set of #s. The F12 I mentioned was bought for $1100 and sold for $1250, over 20 years ago !
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