Antiquarian, you are dead on. And I think the bank thing may be correct. I'll have to search the net and see if I can see "antique coin bank" listed somewhere and get an id. That takes a long time. In the good old days, - and all this is absolutely true - we'd find 25 arrowheads in a day and maybe an ax on Indian sites, my best day on a Rev War site produced 28 musket balls, some go-withs, that is, stuff, and 12 marked "USA" or other regimental buttons.
Once I went to the cornfield at Antietam, decades before it was absorbed into the park and dug 15 minies, half of the bullets Confederate.
Even as late as 1991 I went with a friend to an area not far from the Battle of Saylor's Creek in VA, a few miles from the park, and we got about 200 minies, Spencer cartridges, eagle buttons and two Confederate buttons in 2 hours.
No fooling. These days we are either hunting scraps, or looking for a home site that is long gone we can dig in or a camp the historians got wrong and we can dig. My two farms are the latter. The troops were supposed to be a mile or more away. The historians got it wrong. And with so much land, briars, hills, really hot soil, it's still a hard dig.