69 Dart fiberglass fenders

I have a set of those that I had installed on a Scamp - the lower edge behind the wheel opening (I think that is what you mean by "lower fender brace") on my car had two mounting bolts - there really is no approximating where to make the holes, although I will say I did mine "open" (U shaped) to make it easier to mount them and to allow for some adjust-ability. As for the headlight buckets, I'm not following your question - can you take pics of how you mean angled or straight?