I'm no expert but it looks to me you can just swap out the U-joint and run it. Is the piece inside the right hand piece with the damage the shaft that slips? If so, It looks like your shaft is too long and pushed into the u-joint? I've seen way worse on Jeeps and with some finesse they were usable and they see a lot faster speeds than your blower will. Pound those ears back into shape, make sure your shaft isn't too long and put in a new U-joint and run it, u-joints are cheap. Another trick is to put some tack welds on the caps to keep them in place if need be. When the U-joint explodes on a Jeep while the front is spinning it can and has taken out the lower ball joint (no fun on the trail) so we've adapted ways to help keep this to a minimum.