A bit of searching in the Spanish Google came up with the most probable connection with a Spanish Entrepreneurial family company, founded by one Ignacio Fierro, in the 1940s; They are based in Spain, with Branches in Peru, Equador, and other Latin American Countries, owning Safety Match factories and Tobacco Processing Plants, and Finance Companies( “Banks”)
In Spain, their group is also involved( 1990s etc) in Food brands and manufacturing.
Being a family with Franco Gov’t connections, Might the cartridge be some sort of Commemorative, or similar?
I will dig further into the Name etc;
The trouble is the Fierro name has other , less “nice” connections, being the name of a Colombian Rebel terrorist in the 1990s-2000, and the names of Many people in Mexico in the 1860s, etc involved in revolutions etc…I doubt the ammo is connected at all to these “I.F.” mentions.