Last Mexican Assay Master?

[Aguest]

:::: If anyone happens to have resources on Spanish Colonial Silver, does anyone happen to know the last Mexican Assay Master? :::: I believe CAYETANO BUITRON is listed as working until 1843 (correct me if I'm wrong, he might have worked after that date), but does anyone happen to know who was appointed after CAYETANO BUITRON, if anyone was appointed at all, and if the practice of hallmarking with the assay master's name and a tax-stamp still continued after CAYETANO BUITRON. :::::::

::::: At some point in time in the distant past I remember seeing a list of all the assay masters, and I would appreciate knowing who all the assay masters were, but my primary focus at this point is trying to find out if there was an assay master after CAYETANO BUITRON who may have stopped working circa 1843 or so ::::::: I will try to buy the book on Spanish Colonial Silver, if I am able to find it. :::::: Thanks.