Could use some guidance in putting in some historical metals from Guatemala

I have 3 of 12 metals that were sold by the Fundacion del Centavo, under what they call "Serie Popol Vuh Fundacion del Centavo" that I would like to update the catalog with.  I am somewhat new and have not added any new coins, much less metals, so I am a little concerned about getting it right.  I found a page that explains it somewhat https://www.monedasdeguatemala.com/quetcat.html and I am attaching a screenshot of what I have (3 of the 4 produced in 1976 .   I have emailed the Foundation asking who actually produced the metals, we will see if they respond.

Thoughts on how to proceed?

Tim

It would be better to have this discussion in an Exonumia forum instead of a coin forum. That way people who only collect medals could see and contribute.