For Sale: 600 chainset, Cinelli stem, jersey

"Unfortunately the clamp face is damaged as you see so I can’t recommend using it as is, although it does work."

I have one broken in the same way - must be prone to failing there.

Yep, it seems to be on the brittle side, and not helped by a previous hamfisted owner. I figure someone with a serviceable clamp but the wrong sized stem might want this. Alternatively someone with access to a workshop might be able to fabricate a replacement.