The set screw clutch half is the only one available new; it superseded the 'captive cotter' type long ago. It is also much less trouble-prone.
I'd just get that sleeve off the crankshaft of the late model 'green engine', and rebuild that one. It has 'all the fruit', as regards good options which are available in a Briggs.
The only better option, would be to fit a new genuine Honda engine.
