Wow, that's some lousy welding!!!
With that being said, the tube goes through to the ends of the plate, which means the welds aren't doing a ton structurally. So running them or not running them comes down more to the principle of them sending parts that don't match their pictures and the parts being ugly more than the parts not being functional or safe.
With the length of time waiting for parts and the shipping costs I've had dealing with Mancini I would grind and re-weld that stuff vs sending it back just because I would bet that it would take weeks to get replacements, but they definitely deserve to eat the costs on those.