Gibson has basically NEVER kept good records. (Unlike Martin, whom you can call with a serial number, and they can tell you what size and style of guitar it is, what day it was finished, where it was sold, and who was the original owner. For every guitar back to like the 1880’s.) With an older Gibson, the only way to be absolutely certain is to buy the guitar from the original owner, and to look at the original sales receipt. As long as they bought it in the year it was made, that is frequently as close as you can get.
There are little details, like the volute they started putting on the headstock in 1969 (to keep the headstock from breaking), little things like that. Even with those things, it is still quite hard to date them absolutely.
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