Study this photo carefully
This course builds upon the foundational knowledge of Rickenbacker vibratos that you acquired during your undergraduate studies. This includes the Kauffman and Accent vibratos.
Let’s begin our discussion by examining a unique topic: this vibrato. You may refer to your Kelly & Kelly textbooks, pg 123 for this assignment. (Unfortunately, Professors Kelly seems to have featured a version of this vibrato with a Fender arm, so ignore that... Our example photoed shows the proper arm.) Who would like to volunteer to explain to the class what we’re looking at here? For what models and years was this an option?
From @ronsvintageguitars:
"During 1965 the 425 became a vibrato-equipped model by virtue of an imported Japanese unit, sometimes mistakenly referred to as a ‘Boyd vibrato’, that required minimal routing to the body’s top and the unsightly removal of a corner of the guitar’s pickguard. From this point onwards the single pickup non vibrato model was redesignated the 420. The vibrato-equipped 425 proved an unpopular choice and was dropped from price sheets by 1972." QED