KALAMAZOO

In the late 1930s, the Gibson guitar company decided to offer their own entry level guitars. While similar to models built for other distributors (Cromwell, Fascinator, or Capital) in construction, the Kalamazoo line was originally only offered for about five years. Models included flattop and archtop acoustics, lap steels (and amps), and mandolins.
Pre-war Kalamazoo instruments, like other Gibson budget instruments, do not have an adjustable truss rod (a key difference), have different construction techniques, and have no identifying Gibson logo.
In the mid-1960s, Gibson again released an entry level series of guitars under the Kalamazoo trademark, except all models were electric solid body guitars (except a flattop acoustic. The body profile of late 1960s models then switched to even dual cutaways. The second run of Kalamazoo models came to an end in the early 1970s. These post-war models do feature an adjustable truss rod.
Kalamazoo serial numbers are impressed into the back of the headstock, and feature six digits like the regular Gibson line. However, the Kalamazoo numbers do not match or correspond with the Gibson serialization. Sources: Walter Carter, Gibson Guitars: 100 Years of an American Icon and George Gruhn and Walter Carter: Gruhn's Guide to Vintage Guitars.