Have: Dura Ace 11-23 cassette, 7800, 10 speed, used but OK
Want: Dura Ace cassette, need same but 12-25 or 12-27
Have: *FSA K-Force carbon crankset with damaged left hand crank arm, 175mm
Want: a replacement left hand crank arm, 175mm
*No actual direct swap here, but I do have a bunch of stuff in the For Sale thread that you can see if you want (plus some other items, just ask).