The art on Senorita Rio on #65 and #66 is, to my knowledge, nothing like Jerry Grandenetti.
If it's not Eisner, it's a genius note for note copy.
If it's Eisner, somebody else was inking. But the layouts and the balloon placement and design and the lettering are the best Eisner copy I have ever seen.
I know that Eisner is revered in Brazil but I am not aware of any artist who copies his style so slavishly.
In any case, if you have an artist who was that good, why would you only use him or her for two issues?
Great stuff!
Having been in the business for over 40 years, I've only come across 2 main reasons why great artists were only used for an issue or two, or three, and was not kept on. The first (1) was either that one or the other of the editor or artist behaved incorrigibly, or the two just couldn't work together (bad chemistry); or (2), the artist found that he or she was doing too much work for the pay offered, asked for more money, and was turned down because the editor's boss refused to pay any rate above what they offered, or the artist was too slow to hand in work (missed many deadlines), and so, was deemed unreliable.
My guess is that the artist was young and used this chance to get "in the door" of the comic book publisher, to show the editor what great work he could do. And he hoped that the editor would like his work so much that he could get them to pay him more for his work than the unlivable income rate they paid to beginners. He found that his slavish copying of Eisner's style took him too many hours of work for a low rate of pay that would have been too little to pay his rent and food even if he could do it twice as fast. So he refused to take on more work from them at that low level.
There was a situation like that at Western Printing/Gold Key Comics in the 1970s. A young illustration artist, who had done an advertising job for Whitman (another Western company), told the Gold Key editor that "he could draw like Carl Barks, so the editor tested him out on one story. His artwork looked very much like a cross between Carl's mid '40s and late '50s work (2nd only to Daan Jippes, or perhaps 3rd to Daniel Branca as #2 as a copier of Barks' style. I enjoyed looking at it very much. The artist also wrote the story, which was about average for a non-Barks story of the 1950s, but quite a bit above average for the trash they were writing for Western's cartoon-based comics in the 1970s. The artist discovered that the high number of hours it took him do do such careful work and self-editing to meet his high standard was much too low on a per work hour basis to make it worth his while, EVEN as a hobby, at Western's ridiculously low rate of pay. He would not have enough time left in his workweek to earn enough money to pay his bills. So the artist gave up the idea of being Carl Barks' successor. Too bad! I love his drawing. Not too many years later Don Rosa and a couple other American artists were able to draw Donald Duck and Uncle Scrooge stories for the low-paying US publishers, as a hobby, which allowed them to move on to European publishers, who paid enough to make it worth their while.
Such situations are nasty for fans who love a new artists work, and it disappears with no warning because some people can't work together, or the publishers took advantage of a great desire of many young artists to work in what is a glamour job for them, when, at the same time, the profit margins for the publishers in that industry were so tight.