Your Benotto sounds very compelling. Giacinto Benotto married a wealthy Mexican woman and moved the bulk of his operation to Mexico. He did, however, continue to produce small quantities of bikes in Italy for quite a while. I am betting these bikes are one-ofs, and really close to special production bikes. They also could be experiments from the builders in Mexico City, It is difficult to say. The institutional knowlege of the Benotto concern is not as deep as one would hope, especially if one takes into consideration the cutting edge ideas of Mr. Benotto.
Think of it, one basic geometry for the frames. A tried and true configuration based on decades of race experience. The price of the frame was determined by the quality of the tubing and the braze ons. All frames were Champaigne color and markings were classic Benotto ovals. Each respective frame had a special badge on the seat tube identifying it, but from 50 feet, all bikes looked just like Moser or De Vlaeminks. Mexican builders were trained in low temp silver brazing and were less expensive than the Italian craftsmen. That was the basic idea, then something (I am not sure what) happened. New colors, new graphics, and a bad reputation for some of the Mexican frames.
It gets real confusing because Benotto started to get real goofy with the graphics and the colors, which makes ID more difficult. Alot of really great names raced Benotto's, and Cino Cinelli learned his art from appreticing at the Benotto factory prior to WW2.
Sounds like you have great bikes, enjoy them.