It's a difficult question... even for me. I teach Spanish in Spain. The Spanish spoken in Chile sometimes is very different from my Spanish.
Antidiluviano (or antediluviano) is used, in that context, to express the difference between the ancient world (the world of the natives from Chile) and the modern world.
In Chile, "encanchado" is "elegante": elegant. Then: old and beautiful fishes (maybe fishes that you can't find nowadays... because the jungle is like a paradise).
90% of people in Spain would have big difficulties trying to understand that text.
Good job!