We had a talk from one of these wreck hunters a few years back at my PFA Strut. He was a **** of the first order. Showed us lots of pictures of him with JCB/hole in ground/ holding unidentifiable bit of scrap. He nearly had a sexual climax when he was telling us of how they dug one site even after they had been forbidden so to do.
There may be reasons to dig into some sites for identification purposes but probably very few. I would have thought that we already have enough bits of broken and corroded aeroplane and don`t need any more. Any crash on land is going to be pretty useless as a source of spare parts.
Mike W