Digging Up The Counterfeiter's Den

I saw these many years ago the same week they were found. Here is a group of coins unearthed beneath the brick subfloor of a 19th century building in Virginia. The big coins are contemporary counterfeit large cents most of the Matron Head design (circa 1820s). Mixed in are a Half Cent, the back half shell of a counterfeit Seated dime, the oldest a Spanish Colonial silver one real of 1783 Mexico, a Draped Bust large cent and the newest coin an 1849 Coronet Cent (possibly genuine). The fake cents are elaborately constructed of outer shells with an inner red metal core, and applied edge. Time was not kind to the base metal composition leaving some dateless and most in poor shape. We know Sheffield Plate techniques to make silver plated counterfeits with composition cores of similar style became common by the Napoleonic Wars. Here seems to be a low budget, pre-Civil War counterfeiter's den, or perhaps a legitimate business where bum coppers were dumped through the cracks in the floorboards below a long-ago cash till to keep things honest. Obviously nobody saved these in fine numismatic collections, so they are scarce finds now. Has anyone discovered other hoards, or single cents that split apart showing red centers like these? Who knows the secrets of these long ago craftsmen crooks who spent a dime's worth of labor to cheat five mills the cent?