I have 19th century ancestors in the Darby End area of Dudley/Netherton and on a trip down south, came off the M6 on a whim and went and explored.
All the properties in the area now seemed to me to be modern, post WW2. I was surprised that most of the street names, however, seem to have survived. Whether it's just the names, or the actual layout that has survived, I don't really know, but from having read censuses I think they're broadly in the right place!
Most of my lot had left to go to Lancashire by the 1880s and 1890s, but earlier in the 19th century, this was pretty much a centre of nail-making. If you google for "Dudley" and "nailers" you'll get plenty of hits that give you a flavour of the area and how hard life was.
We might call them slums from the late 20th/early 21st century perspective, but they'd have been perfectly normal working class residences back then.