Or like what adjusted a Burns of London, and later Gretsch neck - sorta like a tuner mechanism buried in the neck heal.
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A special tool was needed to turn it. I can't recall which direction it needed to turn to tighten/loosen.
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I restored a '63 Vista Sonic medium-scale bass and had to address the mangled tr gear shaft.
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Neck is screwed into body and an engraving material 'neck plate' covers the screws. The original was missing and after finding the serial # in the neck pocket, the son of the guy (Edward Cross) who made them for Burns in the early '60s made this one. Pretty special really - talk about legacy! That would be like Leo Fenders son having something to do with Fender today.
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Sorry for the detour - Dano's rule!
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