I know you can't really see it but what there is, is a raised area with the plug screwed into it. Hard to explain, but I was wondering if a welder could weld a nut wher these pieces were and then I could put a new bolt with washer/o-ring. I'm probably just hopeing and will have to replace case. I thank everyone fot the help and guess I'll have to talk to a welder and see if there is anything to be done. There is actually two threads on those pieces but too small to see.