Sorry to inform you but when I saw that my dish was about to fall off the wall, I called a local company thinking that they could just replace the wall bracket and that would be it, but when the engineer asked how long I had the dish up, he said that in that time the specs had changed (wall mount design had changed and also the LNB came already fixed to the arm for easy installation), so in the end I had to have a complete new dish, LNB and wall bracket which cost me over £100.
Although at the time I was a bit annoyed at having to pay out a bit more that I thought, at least hopefully the new dish and LNB should last another 15 years or longer.
To answer your last point the new dish came with a quad output LNB as standard, the engineer told me it was easier for people who wanted Sky in other rooms.
Hope this helps.
*smile*