On the nuts, it depends on if the metal is in good shape right around the hole. If it is, you can take the nuts that were pulled out, clean them, run a tap through them and weld them back in. The hole has been "volcanoed" by the thing being ripped out so that will need repair. I have found that if you put the nut back into the "volcanoed" hole THEN straighten the hole, it will even hold the nut like it did originally.
If the metal is rusted around the hole, then you have to replace that metal and weld in another nut. Sometimes I make them out of flat stock so they look original, other times I just weld a regular nut in. You could also use a "NUTSERT". Then all you do is drill a hole in the new metal and install them.
On the headlamp, without seeing it, it is pretty hard to say anything. I would assume it needs metal replaced and that is how you repair. How much, I don't know without seeing it.
Can you post a picture?