Watch List notes:

Silver "tumbaga" bar #M-145, 3409 grams, marked with assayer INo/DCBCA, YB13, S, fineness iUoiiii (1400/2400, 58.33% fine) and two partial tax stamps, ex-"Tumbaga wreck" (ca. 1528). 12" x 4" x 1/2". Attractive bar (wide and flat) with smooth top (except for small hammer-marks all over) showing most of the explicit (but frustratingly unattributed, also somewhat rare) assayer-mark in center next to a very clear but compact fineness and other markings, the two circular tax stamps nearer the ends, with neatly sliced assayer's "bite" in one corner, no markings on bottom. From the "Tumbaga wreck" (ca. 1528), and pedigreed to the Stuart Auerbach collection (see lot 4), with photo-certificate.
($4000-6000)