Bad news I think about Silver street - It seems only 5 terraced houses remain which could date from the 1800's, on the right hand side of the photo. The telephone exchange seems to have been built in the 60/70's ahead on the rright, and on the left industrial units until the end of silver street. I will check next tiem I'm in the library, I know there are a lot of pics of brecon from the turn of the 20th century.
Better news with priory hill. I would imagine, exce[pt for some 50's housing poking out from a side street it is exactly as it would have been seen during a large part of victorian brecon. The right side has buttraced walls enclosing the cathederal, there seem to be a total of 14 houses on the left side. Off topic, I did find it interesting that some of the pavement is made up of tombstones, some full, some just pieces!!!......I don't know when the cathederal was built however.
I took 20 or 30 pics D, If you would like full size ones I can put them on a cd and post them or email you smaller files as I'm on dial up!!...pm me.
As for the other addresses, I'm still working on them.