Any hobie dealer can get you the parts for the hobie 18 gooseneck. Just drill those rivets out, remove the endcap, then remove to gooseneck part. Put the new one in, and put it all back together. Be sure to use aluminum rivets so that you don't have problems with dissimilar metals on down the road (ie corosion). For the trap handles, assuming that the wires themselves are in good shape (double check them!), go ahead and break off the old handles. I'm not sure if the online catsailor store has them, but I know Murray's Marine has handles that are made to replace those. They just screw together over the wire and work well. Good luck!
Trey
N20 314
Layline Rigging
www.velocitysailing.com