Jethro!, here's pics of the mega-dongle that allows an M1 Air to work with an almost 20 year old iPod. Amazing
Side note: this is actually a backup iPod. For some reason, it will work with the Finder, but Music will not sync. My "main" old iPod does work. I bought a lot of 4 old iPods with the touch wheel. Ended up one had no hard drive and a busted FW port, one of them will work if I swap a HD that has music on it but the iPod itself will not show on the Mac so must be a logic board problem I guess. The two "good" ones are this one that semi works and one that works as it should. So long story short, the iPod has a firewire cable, that goes to a firewire 400 to 800 adapter, that goes to an 800 to thunderbolt adapter, and finally the thunderbolt to usb-c adapter that plugs into the M1.