Both the Airsporter and the Falke 90 were well established by the mid 1950's, so I feel the designer of the Mendoza had seen one of them as part of his rifle follows the same form.
But it is a shame it does not have the same smooth and sleek outlines, the step at the barrel/cylinder junction looks ugly, and the shape of the underlever could have been improved.
But that is just my opinion, and it is the performance that really counts.
It was great seeing you at the show! I can vouch both those guns were very interesting. Kricos are rare and well-made. The little Mendoza is one of the few truly junior-sized underlevers I've ever seen and quite a unique design. it must have been quite a treasure to its original owner!
Mendoza was faring fairly well in Mexico prior to the 1970 Ley Federal de Armas de Fuego y Explosivos (The equivalent of the US Gun Control Act of the same decade, but MUCH more stringent). $ources from the firearms sales were used to develop airguns, and the Mod 4 is, I THINK, quite prior to the 1970's.
Founded in 1911 by Rafael Mendoza Blanco, the company designed and built several firearms that were adopted by the Mexican Army. At his demise, Mr. Hector Mendoza Orozco (son) took the reins.
Recently, the company was split into Mendoza Sports (mainly a marketing company for airguns, archery, and other outdoor activities), and Mendoza Firearms which has re-started supplying the army and the police forces.
Because of all the changes and the "grey" nature of development during the 1970-2000 decades, there is very little documented history.
MOST of the products from the company were sold to rural Mexico, and finding anything from them this old and in almost "new" condition is indeed, extremely scarce.