well, from the pictures it doesn't look melted or cracked....just scorched...i'd look it over with a magnifier for any signs of warping or mircro cracks...if you don't see any you should be fine...if you have a spare insulator it wouldn't hurt to change it out but if not that one should be ok as long as it's form is in tact. It looks like that positive post isn't too difficult to remove and change it out from the pictures. Maybe you'll get lucky and be able to clean it up a bit and make it look nicer again too