Hello, just a quick question.. I have sent my compomotives mo5 to get refurbished, the guy has called me and said that 2 of them have a slight knock and it can't really be straightened because they contain magnesium and will crack.... my question is, is this really correct? I never thought mo5 where magnesium and they weigh a ton and if they are magnesium alloy is there a company that could straighten them as it's only a slight knock??