You need to be careful with the victorian conversions, as the sound really travels in those flats. I can hear my neigbours coming into the building and their foorsteps on the staircase, and pretty much everything they say when walking up the stairs. So, when I am at home, I can say how many people exactly are coming in and out. Not that I care, but if I was suspicious that there was an escort doing business in the building then it would be very easy to notice.
Ground floor flats (or basement) are better for the work purpose as the sound is much more noticable if it's coming from upstairs.
Depending on the sound insulation, which in some cases might be non-existant, you must really work out your neighbours' routine before starting any real business from home.
Some victoria conversions I have lived in, I couls hear every word and every step, it was more like sharing a flat with the neighbours!
If you do move in, give it a couple of weeks to see if the neighbours are out during the day and then start bringing in limited number of people.