Looks like overspeed or maybe they jammed the tines and sheared the crank...
If the ring gap looks good I wouldn't even change them (rings), unless you see that it's burning oil..
CHeck the trottle shaft, It may be gummed up / Stuck in the full throttle position.. (causing the Break).. Tillers on the average only run twice a yearfall and spring..
When you go to put the clutch back together, take some scotchbright (fine grit, blue or gray) and clean off the crank-tit that rides in the pawl assy. Get off any brown baked or gummy residue on it make sure the unit is clean and smooth (lube with a light White grease) or the unit may start to hang up and destroy your rewind assy..
Good find-- nice unit...
Friiy