Thanks, Blue' ; always nice to see Thorn stuff come up on eBay.
I think perhaps the seller might have mistaken the clear-anodized silver stem for stainless here. Or, since "alloy" is in the title, perhaps they are referring to the bolts and hardware.
Still, that's what makes eBay so interesting; it's the World's Biggest Garage Sale, and *any*thing is possible there! Even when I'm not looking to buy, perusing eBay makes for good entertainment and endless speculation.
Best,
Dan.