Here are some sites that I found when I was running a brief New Mexico-based T2K PbP a few months back. The first site has pics of several IRL Mexican AFVs. The second has lists of said, including the numbers fielded (I can't vouch for the accuracy of the figures, but it's a start).
https://aw.my.com/en/forum/showthrea...mored-Vehicles
http://www.armyrecognition.com/mexic...tion_desc.html