Get motor model number and call Tim's outboard 218-682-2331.. they may have a good used, or quote for aftermarket. Did you check the forward/reverse mating surfaces?
There certainly was a 1972 20hp. Model 20R72R (20RL72R for long shaft). Clutch dog is part number 316501, replaced by 390030 dog and cradle assembly. They're not hard to find, just hard to pay for at a list price of $141.64. I have one left (new) for a lot less$$. Send me a PM if interested.
There just is no way to know what it needs without going in and examining it. And once you are in there, knowing what you are looking at. Most people will look at a worn out dog and gear and say it looks fine. It takes surprisingly little wear to make them jump.
