Thanks!
Yes, the saddles are held in place just by friction and string pressure, which is enough, after setting the intonation I made small marks for him to be sure where to place them when he changes the strings. There are two screws from the bottom that can raise or lower each string, but I will probably make another set of saddles that I think I will like more, pretty simmillar to these, but with more flowing lines.
Use boiled lineseed oil, at least I did, good quality thinner for oil finishes (mineral thinner) or turpentine, and you should find varnish in the same shop I think. Paint section of the home improvement stores should carry it. If you want to do it like I did, make sure to add 0.5 extra unit of thinner, because you won't be wasting much time waiting for it to cure. If I recall right, I have 6 coats of oil on it, one per day, and four coats of wax paste, 2 per day.
This is a first time I've used this kind of finish, so it could perhaps be done better or differently, but I like the result which I got. The wood was sanded up to 800, and also between the coats of oil.