I will say one thing, it looks to be in great shape. "The paths of experimentation twist and turn through mountains of miscalculations, and often lose themselves in error and darkness! You can generally date a Kalamazoo by the features such as the headstock shape, etc. Product ID=5978, sold to me thru a third party).7931H (it's a FON) is a 1942 KM-12. I'm surprised they would stamp a FON on the outside, it isn't their usual way of doing things. " --Leslie Daniel, "The Brain That Wouldn't Die." "The days tell, the years speak, the centuries decide . but there are FONs listed for them in Joe Spann's book. None of the Gibson 2nd lines had truss rods (although I did see one later Kalamazoo that did have one). According to Retrofret's description the number is actually 7930H - this is a Gibson FON, not serial #. The adjacent FON 7931H is listed in Joe Spann's book as KM-12 batch.The top and back were pressed and not carved as mentioned above.
Reintroduced in the ’70s with a more traditional mahogany body, it then became popular amongst rock players.Though Gibson tried to make a splash in the market by giving its Les Paul model a fancy maple top and sunburst finish, the guitar failed to truly catch on.Its status changed dramatically, though, with the 1966 release of John Mayall’s Blues Breakers featuring Eric Clapton.Leo Fender’s first Spanish-style guitar was also the first to incorporate a “bolt-on” neck, which lent well to mass-production.Its single-cutaway design is simple, and its workingman’s appeal never waned.One of the models that mark evolutionary changes at Martin, with the advent of bracing for steel strings in ’28, values jump.