quick search shows...
https://www.probikekit.com/bicycle-b...ation=11070668
and there are any number of vids showing installation... You MIGHT find a single right on Ebay... kinda scarce as a single... they fail fairly often.
you might find a campy replacement PART that might fix the assembly... kinda tough to do, if possible... get the new assembly, since the return spring fails, too.