A Dozen Pesos De Ocho Reales

More than a decade ago, I purchased from an LCS a dozen colonial Mexican 8 reales -- each chopmarked, and severely cleaned; dates 1787-1807. They were sold at (or maybe below) bullion, and I trusted the LCS not to cheat me, but I wondered if they were all good silver.

The LCS (under new management) bought an XRF gun, and tested them for me today. Six were 90%; 2 were 93%; 2 were 95%, 1 was 97%, and 1 was 99.3%. I did not believe any were regal, and I was right--no trace gold. However, I was surprised by the spectrum of results.