The Elephant in the Living Room compiles the research of six authors who show the errors in the modern Spanish Bible, particularly the 1960 edition.
AV Publications carries good Spanish Bibles.
Riplinger's chapter has:
Historical precedence for translating foreign Bibles directly from the KJV and other Holy Bibles, when an old text does not exist. This side-steps questionable lexicons and currently printed one-man editions in Greek & Hebrew.
(See web site's 'RESOURCES, FREQUENTLY ASKED QUESTIONS, # 13', for details.)