The sixth number is now a batch number- batch 0 starts at the beginning of the day, and once we stamp 699, the batch number will change to 1.The first 5 numbers remain the same, the last 3 numbers will remain the same.FON consists a batch number of usually four digits, followed by a one letter (sometimes prefixed by a space) followed by one or two digits (ranking).1935-1937: Letter between the batch number and the order number. 0123 A5 1938-1941: Two or three letters before batch number. If there is a second character follows it is the code for the type of the instrument.The only difference is the addition of this batch indicator.Les Paul Classic: This model features an ink stamped serial number with no “MADE IN USA” (just as we used on the original 1952-1960 Les Pauls).1977-2005 Gibson introduced the 8 digit serialization method.
YDDDYBPPP YY is the production year DDD is the day of the year B is the batch number PPP is the plant designation and/or instrument rank.(G = Gibson, K = Kalamazoo, W = Recording King (Montgomery Wards).If follows there is a third letter E, it stands for Electric.For more details on Gibson Serialization prior to 1975 and historical product specs, use your Gruhn’s Guide or view the following PDF files: Since 1989, all Gibson acoustics are built in Bozeman, MT and all Gibson electrics are built in Nashville or Memphis.Ranking numbers for Bozeman start each day at 001 and the electrics may start as low as the 300s.