Todd, I was looking through the forums and saw your cry for help. I don't think there is a more difficult place to hunt than the one you describe. I have in frustration gone to patterns and use edit to black out all but the top upper right part of the screen and be able to pick through trash for silver. I then slowly expland the open area and try to get the gold opened up. I know what you hear about learning the tones and you can eliminate nails by tones but I have never seen any one do it IN THE REAL world and in person but if they can really do it then I would love to see it. VLF detectors LOVE IRON AND NAILS so we all live with the problem.
Here is another one that I do in desperation. I use learn edit to reject the trash that is the greatest problem and go for what is left.
Those old home site if there is a lot of nails and other trash are enough to make a grown man cry. You just about have to clean out some of the large trash metals to really do much good. I guess that is why I hunt the ones where the house is still standing. I have picked through some of the others for years as I could only stand it for a short time and then had to go to another site and come back off and on.
Good Luck,
HH, Cody