The numbers for each year typically overlap, as there is always a transitional period between successive years and as necks and complete instruments that were made and serial numbered late in any given year were used on instruments assembled and sold in the early months of the subsequent year.
As always, dating by serial number is not an exact science and is seldom definitive.
I play a Flatiron, are there any other Flatiron pickers out there? Jazzrambler, you have a very early flatty, the stamp on back of the headstock being an indication.
My understanding is the company was bought out by Gibson and then shut down after a few years. "The FLATIRON" stamped on the back of the headstock. The first 2 numbers in the serial number are the year, I'm guessing '80-'82 or 3?
I had '72 Gibson F-5 that looked very pretty but had practically no projection at all. Yes, some time in the late 80's Gibson got tired of the competition since Carlson and his staff were building and selling much better instruments at cheaper prices and Gibson bought them out, and took Carlson and a few of the workers to the new Gibson shop in Nashville.
Very heavy construction, but I used it for about ten years. But some of the workers did not want to leave Montana (who would?I tried to have it repaired but it needs more work.I've changed the top 7 frets once already and they're getting pretty worn now.Another thing to look for is whether the numbers are too close. The fake one on the right has no serial number at all. You can search for your serial number at The Guitar Dater Project. It will return the birth date of your guitar and the manufacturing plant. Also the rest of the body finish is cracked from, I assume being too cold.It's model #21A, serial number 81071030 by Back Porch Productions in Bozeman Montana.Gibson continued to make the mandos after they bought & moved the company to its Nashville plant, but the Montana ones are highly sought after and get a good resale price.A few folks at the Flatiron plant decided not to move to Nashville with Gibson; they stayed behind and started their own company, Weber (or Sound To Earth Instruments).I have a 1992 Flatiron Master model F5 that I bought new in December of that year.I've enjoyed it a great deal, just wish I could do it justice!