Thanks, Hugo. This is a bit of a conundrum. Looking at the old OS maps, Cwlach Street ran along the backs of houses in Church Walks as far as the steps to Haulfre Gardens/Cwlach Road. In the 1939 directory there were 19 dwellings there. 14 on the NW side and 5 on the Church Walks side. The 1861 "Directory" paper I referred to only has 7 properties listed starting at Caersalem. I will list these and the named occupier or head of household:
Bodnant - Mr R Lester
Bronhyfryd - Mrs Hughes
Brynhyfryd - Mr W Jones
Brynhyfryd (2) Mr P Jones
Bryn Maenan - Mr Abel Roberts
Valley View - W. Green Esq
Daisy Bank Cottage - Mr Peter Roberts
I wonder if some of the dwellings in the part of Cwlach Street below Cwlach Road have been subsumed into other properties over the years. Sorry not much help with Queen Street, although I have heard of it before.