bannockburn; I have vague recollections of reading about something of that sort, but can't recall exactly where or when. The closest guess I can make for the first time would be in the early-to-mid '60's when I started buying my own magazines and got interested in the works of Rex Applegate, Elmer Keith, Ed McGivern et al.
It was likely in something by Col. Applegate, as he did a lot of consulting and training work in Mexico and South America. He held a General Officer's commission( "honorary", I believe) in the Mexican Army at one time and frequently incorporated anecdotes about his experiences there in his articles.
I also believe that one or another of my later favorite writers in the '70's (may have been Bill Jordan, Charlie Askins or Skeeter Skelton) described firing one in Mexico but, IIRC, it was a CF model.
All I can dig up so far on Mendoza is that they used to be something of a big player in the domestic military and civilian firearms and ammunition markets of Mexico and Central American countries but eventually were reduced to just making air rifles.
There are mentions of some strange and ingenious "end run" products that they came up with to try and keep some sort of useful, practical and affordable firearm available to Mexican civilians, especially in the hinterlands, while staying within the increasingly restrictive and draconian laws there.
Besides the aforementioned pistols, there were a line of single shot and repeating longarms, mostly RF rifles and shotguns, and even some "hybrid" muzzleloading shotguns that used .22 blanks for primers and smokeless powder.