Looking for the correct chrome fixing nut for Campy super record brake pad holder. I need one.

I need this:



to replace this:



Have plenty of good stuff to trade but, that said, I certainly don't want to break up anyone's correct set. I found the one by picking through the bins at the LBS. If there is another source for this I would certainly order one, but I've looked and everything seems to come with pads or brakes.