I live in one of those half houses and having just been outside with the picture on the ipad I can say with certainty that this is one of the houses along the row.  Due to the guttering and slope of the ground, I am guessing its either 195 or 199.  Interestingly, 197 still has many of the original features shown in the picture - same pathway, same front door, same 'bullnose' detailing, same roof detailing, and same porch tiling.    p.s.  I did a major renovation on my house and can also say with certainty that they were originally built as half houses - not converted later