A John Brouster, Glenhall, died 1844, aged 90 is buried in the Camus graveyard.
There is a John Broster in the 1795 Flax Premium List.
The 1828 TAB has a John Brewster from Glenhall holding 8.1.3 acres.
There is also a John Brewster living in House 10 in Glenhall in the 1831 census, the head of a household of 3 males and 3 females, plus one servant. This sounds like the same person - a relatively well off farmer. Also, he is living next door to a James Brewster, in House 9, who is the head of a household of 5 males and 4 females, which suggests these men may have been brothers who shared a bigger farm.