Is this translation of a note in a map correct?

Question

I just saw this tweet. It contains this image:

(taken from here, where we gather that the map was drawn in the early 1700s)

with the following Latin sentence:

ex septentrione longissimeque dissitis regionibus venisse ductuque mirabili migrasse versus meridiem mexicanos olim incolae produnt.

(I think, please double check that I have typed it correctly)

Am I correct in saying that the translation is the following?

From the northern extremely distant and widely removed regions, came through marvelous guidance and migrated towards the south and [became mexicans?]

Unfortunately I can't make full sense of "mexicanos olim incolae produnt".

Answer 1

The phrase is a bit difficult because the subject and verb are waiting at the end. Here's a better translation:

The inhabitants state that the Mexicans once came from very far removed regions in the north and migrated towards the south in an incredible journey.

The basic structure, in English reading order, is as follows:

• Incolae produnt... - "The inhabitants state that..." (setting up an accusative with infinitive)
• ...mexicanos olim venisse...[et] migrasse - "...the Mexicans once came...and migrated."

The rest (describing how they came and migrated) is pretty straightforward and correct in your translation. I translated ductus as a "journey" (with an implied leader), but "guidance" also works fine.