The numbers 001-499 show Kalamazoo production, 500-999 show Nashville production. When acoustic production began at the plant built in Bozeman, Montana (in 1989), the series' numbers were reorganized.
Bozeman instruments began using 001-299 designations and, in 1990, Nashville instruments began using 300-999 designations.
Because of the constant changes its been through, he's never known what year it is, mainly due to the serial number being mostly removed. They explain that over the years Gibson has used different serial number schemes so it's not always too easy to find the unique history of a guitar.
The one thing he never removed though was the original Maestro tremolo as he states "It's the look.
It's the kind" even though it ruins tuning stability. Here is a site furnished by Gibson that should be some help.
A few bolt on neck instruments had a date ink stamped on the heel area.
In 1977, Gibson first introduced the serialization method that is in practice today.
The orange labels inside hollow bodied instruments was discontinued in 1970 and were replaced by white and orange rectangle labels on the acoustics, and small black, purple and white rectangle labels were placed on electric models.
All numbers were impressed into the wood and a six digit number assigned, though no particular order was given and some instruments had a letter prefix.I'm sure that one of the senior members can be more precise then myself and give you some more interesting tidbits.Oh yes and by the way, if you can share some photos, everyone here would be delighted to see them.I'm lucky enough to say that the Rock Gods have bestowed upon me a vintage Gibson SG. It was a gift from my father when I was close to 8 years old, as I was angered when I found out that "the pretty guitar was sold" (which turns out it was pawned for some quick cash).He told me he "bought it back" and that it would be "mine" so he couldn't do that again after seeing me get so upset.My dad purchased it while he was still living at home with his mother and the money he used on it was supposed to go towards a new car, I believe.