The key to relic hunting successfully is not to count on luck but to count on research (I just made up a quote whoa) good luck my friend.
If you would like sometime in the future if you get frustrated and not finding anything back behind your property for free I will be more then glad to ride over there on a Sunday and look @ the lay out of those trenches/land and see possibly where you could find stuff by doing soil samples and eye balling low depression points in the ground and dig a few test holes in the trenches...