just sayin here
Many times when looking at a veh at a car show , one of will say " wonder if its metal or fiber glass " . Then we discretely try to feel it to find out . Conclusion , if we can't tell with out touching , what does it really matter . You have had this car - up close - for a while and you didn't "know" till you started digging . Conclusion , what does it really matter ? . As long as you don't miss represent when you sell it and you drive it and have fun doing it - after all it's all about having fun isn't it - bondo it back up and drive on . If you can't drive it "as is " then patch away till your having fun .