After a search going back over a decade by various individuals, the original 1.0 firmware which shipped with the iPod Classic 1st generation in 2001 has finally been dumped and preserved thanks
Apple IPOD CLASSIC - 7th Gen - Grey - 256GB SSD - Massive Upgraded Storage!
iPod (1st generation) | Apple Wiki | Fandom
Vintage Apple iPod Classic M8541 5 GB - 1a Generazione - Bianco - IN PERFETTE CO
Apple First Generation iPod Classic, Bob Marley Special Edition | RR