Little point in leaving stuff there I suppose. It will just rust away further over the next hundreds of years. Better to concentrate resources in a few of them.
Sorry, I posted this and went to sleep so missed the replies. We have one complete and open to the public. We were allowed to dig out the bunker entrance to explore & recover anything interesting, then it had to be sealed back up. The last time this was done was in the 70's, as it is beach-side in an environmentally protected area.