Watch List notes:

Large "plata corriente" piece cut from thick silver "splash ingot" with clear tax stamp, 81 grams. Roughly 1-1/4" x 3/4" x 1/4". A substantial chunk of silver, clearly broken on four sides from the interior portion of a large disk ("splash"), with abnormally distinct tax stamp on smooth(ish) top that shows (D)G:ISP(ANIARVM), presumably of Philip II (1500s), the other side rougher (as made) with light encrustation in crevices, its weight exactly matching that of three 8 reales. XRF test results: 87.85% silver, 7.14% lead, 1.17% copper, traces of other elements.
($500-750)