Mexican Dirty War Medallion

This is a commemorative piece made from a 1968 Mexican 25 peso piece which would have been the Olympic coin. It was modified by a jewler or someone with great skill to remember the Mexican Dirty War period the two dates of 10-2-75, and 5-7-75 are two events occurring in this time period. The J.E.F. stands for the Jesus Escarcega Faculty that represented attack on garrison of Madera in 1965. The main triangle diagram is the Escudor of Chihuahua for Courage,Loyalty and Hospitality. I cannot find another of these anywhere. It was obviously made very carefully and may have been awarded to people involved in the Dirty WAR period in Mexico. Any info would help.