Thank you George, that top photo is great! I seem to have misplaced my 1913 map where I had marked where I think 331a Canon Street was. I think it was on a corner but I don't remember the name of the street. My 1895 map only shows Severs Street, just a small road with only a few houses - perhaps it was in the process of being built in the 1890s. From memory I think 331a was a bit nearer Newport Bridge end, so maybe it was Cooper Street, or another street that isn't shown on my 1895 map.
I will have to have a good search for my 1913 map to see which corner it was!
Thanks for the info, much appreciated.