The ’58 model year Gretsch introduced many significant changes to the 6120.
· Clearly the most signifigant change is the new “humbucking“ Filtertron pickup. Early versions of the pickup have nothing written on the top and they are often referred to as “pre-paf” filtertrons. The plastic surrounds are typically unscuplted on these early versions as well. Later in 58’ the pickups have “patent applied for” on the top and sculpted surrounds.
· The trestle bracing system. Gretsch introduced parallel braces with a “trestle” style brace between the top and bottom of the guitars interior. These early 58’s have the braces on both the top and bottom of the body and run the full length of the interior. These early braced guitars are typically quite heavy!!
· Ebony fretboard with neoclassic (a.k.a. thumbnail) fretboard inlays. The rosewood board is no longer on 6120’s.
· A tone switch (a.k.a. mud-switch) took the place of the previous tone control knob.
· A dowel was also applied to the neck-heel, revealing the addition of an anchor screw, to better reinforce the suspect neck-joint.
· The bigsby evolves from the cast aluminum spoon style (early 58”) to a pressed steel handle (late 58’).
· The “bar” bridge replaces the bigsby bridge.