Trying to help out a friend. I think its a 10pin molex connector that allows you to hook up kick buttons to the CP. If you have something like this, PM me with price incl. shipping to 93003.
I just sold a SF2 board and the kick harness is still in the cab I would sell it for 10 dollars shipped. Otherwise a new one can be had from jammaboards.com.
Simple enough to make, but Bob sells them as well (search for SFII on the Parts page). He sells them in two pieces - the PCB side and the CP side. They connect together by a 6-pin molex so that they can easily be disconnected and/or switched between games/control setups.