I've got three extra now...I replaced some 'fixed' ones with 'adjustable' ones on my C. I had problems with loose rear wheels. I now have three of the cam bolt adjustables on each wheel with one fixed one on each wheel. The one in your picture is a 'fixed' and I'd send one or two of mine to you if you still need one. I'd like to keep a spare, but probably only need one.
Let me know if you want one or two of mine.