Looking at Northdown Street
On the 1969 1:1250 map number 37 is shown on the west side of the street and ~ 3 houses south from the junction with Collier Street.
The 1910 Valuation map is based upon a map labelled with NORTH STREET but 'DOWN' has been inserted in a smaller typeface in the space between the two words. The properties are variously referred to as Northdown Street or North Down Street. The no. 37 property is in the same place as defined above.
In the Valuation Survey, no 37 Northdown Street was occupied by someone named Barber on a monthly tenancy, rent £44 per annum (I calculate that as £3. 13s. 4d per month). The property extended over basement, ground, 1st and top floors with two rooms on each level. A fuller description for nos 27-39 is included with no. 29:
G.F. 2 & W.C. Good entrance hall.
B. 2, W.C. W'ho in yard.
Area to front
1st 2, with balcony to front
Top, 2
This matches perfectly with the external appearance of the existing houses on street view.