While I know quite a bit about Thunderbirds (from this thread and my own experience), others here a far more knowledgeable than I. I suspect someone will have some answers, but if that is a 1 of only 2 in black, of a run of only 20, I'd guess someone might be willing to pay a lot for it. Trick will be finding that "someone". If it's not from the '70's, then I'm thinking it's from the mid-2000's or later because, I think, Gibson re-started making Thunderbirds in the late 80's right up until recently. They had ebony fretboards until the mid 2000's, and II's, as far as I know, were not made, or available at all from Gibson regular production in that era.