[rotorwrench]

Those shavings or metal pieces likely came from inside the upper switch ring body. That switch ring with its insulator are attached to another part up in there. The switch control spider fits in there to rotate that assembly to function the switch. There are pieces of metal that are bent over to hold the switch ring & insulator in place. If the resistance to turning was too great, some of that stuff may have broken off up in there. I don't know where else it could have come from. If A&L make a switch body, theirs would likely be better than anything else in the reproduction world. Originals can wear out too but they were pretty sturdy if you can find one that was lightly used and stored well for 90 years.