I would like to know origin of PD4107-325
Big John -
PD4107-325 was delivered new in May of 1966 as fleet number 5100 to the Southern Greyhound Lines division of 'Hound, who's corporate HQ at the time was Chicago, IL.
Back then, Greyhound's maintenance was the envy of the industry, so for this coach's first 10 years or so, it was well maintained.
Most likely, Greyhound sold it off after the summer season of 1976.
FWIW & HTH. . .
;)