Just seen the tuning keys are not originals.
"Vintage Gibson serial numbers
Gibson used various systems of numbering their instruments, and some records exist that can give a clue to a shipping date. 50s and early 1960s details are fairly straightforward, but later serial numbers (particularly around 65-75) can cause more confusion than clarity. BEFORE you read the Gibson serial number charts, please read the rest of this page!
The serial numbers Gibson used, particularly from 1969-1979 are often very difficult to interpret. The reason being that Gibsons 6 digit serial number system reached 999999 several times; each time they continued from 000001.
So Gibson re-used serial numbers. If you read through the charts for a hypothetical number, say 123456 - we see that it was shipped in 1963, 1970-72, and again in 74-75. Not an ideal situation, but many of the Guitars we see listed for sale as 1960s instruments, are actually newer. It is often not the sellers fault, as they will have looked through the numbers, found it was 1963, and would see no reason to look further in the document."