Both are excellent references and may be quite helpful to you in both determining the year of production of your instrument as well as identifying specifications and a historical context for the instrument.
Unfortunately, the records of Guild serial numbers prior to 1960 are somewhat sketchy, and so we are unable to assure the accuracy of dating before that time.
This is the Fender Rhodes that you will hear on an introspective journey through Miles Davis’ Bitches Brew or paired with Bill Evan’s Steinway on From Left to Right.
The instrument evolved from Rhodes' attempt to manufacture pianos to teach recovering soldiers during World War II under a strict budget, and development continued throughout the 1940s and 1950s.
Fender started marketing the Piano Bass, a cut-down version of the piano, but the full-size instrument did not appear until after the sale to CBS in 1965.
The company was eventually sold to Roland, which manufactured digital versions of the Rhodes without authorization or approval from its inventor.
In the 1990s, the instrument enjoyed a resurgence in popularity, resulting in Rhodes re-obtaining the rights to the piano in 1997.