At first I thought is was a 67 since the serial number was said to be in those years.

After more reading on the gibson's website, they said that the MADE IN USA was added in 74-75 along with serials in the same range as mine.

But as you said, they messed around a lot with their serials and mixed them up without real defined patterns. Or maybe I just don't get it.

If you say the wiring is bad then My problem may come from this. I have a lot a noise in my sound. I didn't realized it until a few months ago when I recorded on my computer. Man! The backgroud noise is really loud. Now that I think of it, it feedbacks a lot when I play with a band.

I guess the wiring should be redone.