From my reading, one section of text appears to read "Luz y D.o Florez"
As a Spanish-speaker, I take it as the names of two people-- "Luz" of course means 'light' yet it's also a perennially-popular woman's name.
I take "D.o" to represent an abbreviation, either of a man's name, perhaps such as 'Diego' or 'Domingo,' or else the abbreviation for any Spanish participle ending in the masculine "-do" as illustrated by such common abbreviations as "Sdo." for "Segundo," or "apto" for "apartado" or even "1.o" as the abbreviation for "primero" (first).
As someone else had indicated earlier, Florez is indeed a fairly-common surname, so the phrase might logically be a graffito of a couple, a man and woman.
Considered from another perspective-- If indeed the text shows an abbreviation, it would follow that the shortened word would have to be so well-known as to tolerate abbreviation. If the word isn't a man's name, it's even possible that the abbreviated word might even be "D[orad.]o" meaning "gilded" or "golden" which might mean that treasure is nearby 8)
I'd be interested in seeing close-up photos of each individual figure or group of figures.
E