The image below represents my (crude) drawing of what is likely a personal coat-of-arms that appears inscribed on an artifact excavated in Texas; although currently undated, most-likely from a mid-16th-thru-early-17th century context.
I have provided my interpretations (labels in the image), so far, as to possible identities (whereas the 13-stars undoubtedly represent the Salazar lineage, I am far-from-certain of the two-headed eagle [aguila bicefala], which was a very ancient heraldic symbol [e.g., reputed to have been Julius Caesar's], but likely here the imperial icon of a Holy Roman Emperor, perhaps Charles V ... or possibly the Estrada lineage, who were [along with Hernando Cortes, as another early example] among the earliest non-royals granted the imperial privilege of using this symbol in their armorial bearings ... though, so far, I have found no record indicating any prominent Estrada ever did actually use it).
Any hints as to whom this escudo may have belonged [or how I may further research this] will be greatly appreciated!
I suspect it MAY have belonged to Gonzalo de Salazar (Charles V's imperial Factor in Mexico ca 1524-1540s); or one of his sons, sons-in-law or a nephew; the Factor was known derisively as "El Gordo" ... but I have not located an image (or description) of his personal coat-of-arms, although I have recently seen a reference indicating that it was among the exhibits of Mexico at a national celebration in Madrid ca. 1920s.
PS - I have already searched-through THOUSANDS of historic (late-15th-thru-17th-c) printed armorials (and archival sources), to no avail ... so, please, do not bother recommending more of that ... I've more-than-likely seen them all!