Guys - we may ALL be wrong on this one (as amusing as this thread has been in places)
I checked some info from Gibson's website
http://www.gibson.com/en-us/Support/SerialNumberSearch/The top link gives a downloadable article on serial numbers
An extract from that PDF on Gibson Serial Numbers reads:
From 1970-1975 the method of serializing instruments at Gibson became even more random. 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. 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.
In 1970, the words "MADE IN USA" was impressed into the back of instrument headstocks (though a few instruments from the 1950s also had MADE IN USA impressed into their headstocks as well).
Year(s)
1970, 1971, and 1972 1973 1974 and 1975
Approximate Series Manufacture
100000s, 600000s, 700000s, 900000s 000001s, 100000s, 200000s, 800000s and a few “A” + 6 digit numbers 100000s, 200000s, 300000s, 400000s,500000s, 600000s, 800000s and a few A-B-C-D-E-F + 6 digit numbers
So the guitar may well be a 70s Les Paul which is a nice thing to be given and actually what the OP thought the guitar was in the first place...........
However there is a slight difference in value if sold