Ok, now the situation is clear. There is zero chances for a Sabayon beginner to make such printer work. Thanks a lot.
However, let me extend the above phrase. There's zero chance for a middle level Sabayon/Gentoo user either to make such drivers work.
The reasons is that the level of experience required to make such printers work is so high that even probably most of the users of this forum (way more experienced than me on Sabayon/Gentoo) would be able to. This is not an offending sentence. It is just to realize than even though I become a middle-level user (middle level means: perfectly know how to use and configure the most important/used applications of the system, that may require at least several months) I would never be able to use such printers.
Discussion in general that pertains to Sabayon Linux - Must Pertain to Sabayon Linux