No, but I have a theory about this. Silver dollars laying flat probably sink very slowly in most soil conditions. Hence, the first guys to hit major hunting areas with their BFO and older detectors cleaned up
on these large coins long ago (50's,60's, 70's).
Now if it is on edge, it has a chance to sink much deeper in ground to who knows what depth but certainly out of range of BFO and older detectors. But with today's detectors, that must be an ear blasting sound - a Silver dollar laying flat.
Still how much of the earth and ocean will never have a coil pass over it? They are still out there waiting for some lucky TH'er! HH!
I took care of my itch for a piece of eight when I ran into someone whose dad was involved with Atocha recovery and they had a couple on display in a museum. When asked if a could buy one - they very kindly gave me one for a contribution to their museum.
They mentioned no price but I looked up value and gave them that. A piece of eight is what our Silver Dollar was based on in size and weight, or so I was told.