In addition to what John said, I recommend adding updated bushings (Part #8062001) to each casting. I used two on each side of my old-style castings, one on the top and one on the bottom - makes a big difference) The bushings tighten up the system and reduce unnecessary movement/pin wear. The white one shown in your picture at the top of the broken pin appears to be terribly outdated and worn. I don't see a similar one on the bottom (maybe not required on the newer castings?).
'82 Hobie 18 SE with '85 Nationals Prism (White) sails
'73 Laser HID# 3463