I have a 1960 johnson rds-22 motor on a 13 foot boston whaler boat. For the last two years it runs great!! But this year it started making a clunking sound. I checked the linkage which was ok, and then decided to take apart lower unit. The clutch dog was rounded over on the edges, and was wondering where to get new one? the brp catalogs only go back to 1968, will that year of parts be same as 1960? thanks!!!