It does look grim, but I suppose it would not come off, just no need to swell those rivet ends by more than about 15 thou, it looks like he achieved about 400 thou.Lets face it on racing 750's the works did at one time weld the sprocket flanges to each other to stop the keyway shearing, that must be grim as well, but obvously worked. (the "Aviva" moment?)
CLEM