I found this on-line about this map.

http://patepluma.sphosting.com/patemaps.htm


GUATEMALA & BELIZE
These maps were scanned from a 1990 map published by the Guatemalan government printing office. This map is believed to be in the public domain. As Guatemala officially claims the nation of Belize to be a Guatemala province, that country is shown on these maps as a part of Guatemala. The maps were scanned at a resolution of 200 dpi.