Circa 38 mm and 27 grams would be correct. Some kinds of corrosion proceed in such a way as to leave features intact, but I can't see how that could happen to this extent.
24.5 mm would be smaller than a 2 reales piece (it's about the size of a current US quarter), which would require an uncommon thickness to reach 21 g. I might believe 34.5 mm.
24.5 mm would be smaller than a 2 reales piece (it's about the size of a current US quarter), which would require an uncommon thickness to reach 21 g. I might believe 34.5 mm.























