Many mints were operated under private lease. My first guess would be that most documents, including production figures, stayed with the company and were not sent to government / state archives.
Actually, I would say that even on a worldwide basis, most coins are cleaned, if you take a closer look at them. Some more expertly than others. But in public sales and dealers' lists, usually only the better (i.e., not badly cleaned) ones show up. So it's not just the 8 Reales. However, comparatively less 8 reales survived in uncirculated condition than, for example, Morgan dollars. Truly mint state examples with few bagmarks (which end up in these plastic coffins as MS64 or better) are really, really scarce and even unattainable for many DAMs.



















