The bracket is welded up from some tube and bar. The nuts on the stainless steel threaded rod can be adjusted to sightly bend the pole forward or back to fine tune the elevation. (Although in my experience, elevation is much less critical than azimuth.)
To aim the dish, I use one of the satellite aiming apps which work with Google Earth to establish landmarks which are in the correct direction. Having got the dish in the right ball park, I get the TV outside with the Mk1 Sky box and observe the bars on the signal strength and quality indicators and fiddle around until I get the best result. I then fiddle with the LNB, in out and skew but that doesn’t seem extremely critical.
Results are mostly good but weather conditions can seriously affect reception.
Incidentally, I tried a 150 cm dish and that was much worse than the 120 cm! I think I read somewhere that a big dish needs a different type of LNB.