Reinforce
I've got an 88 Legend 35 with the same problem. I had the Boat in Charter for a couple of years before I personally took it over, one of the reasons being 2 years in a row, the chain came off the sprocket. They also bent my steel emergency tiller. Didn't know about the Rudder Stop problem until I was getting ready to put the Boat in this year,and was looking for water leaks. On mine, the backing plate behind the stop plate is plywood. Found that out by removing some of the fiblerglass on the backside where the nuts are secured. I dried it out the best I could,and installed a larger backing plate on the backside,made of aluminum. On the rudder stop side, I repaired the fiberglas and reinstalled the Stop. Can't tell anything was ever wrong now.