I did a search for "centerboard stop" and someone said to remove screw on top of centerboard for bungee cord. Removing that screw, the broken off stub pushed right out. It is hard rubbery type plastic. Now my question is how long should the new one be and should there be rubber over the ends that will stick out?
In liew of a 1/2" x 1.5" piece of delrin rod, I picked up a piece of 3/8" (id) pipe at Lowes for abt. $1.40. As it's 3' long, I have enough to last a lifetime. Took screw out, slid broken stop out, slid new stop in, replaced screw. Took all of 5 minutes, and only that long because my wife was bugging me about something. May only last a couple seasons, but couldn't be easier to swap out.