Hi John
I googled Westcott Terrace Sunderland and found the following, which is amazing actually as I worked for Sunderland Public Works Department in the mid to late 60's as a clerk on building sites and one of my small sites was on the west side of Brandling Street and I had never heard of Westcott Terrace. Brandling Street is still there, near the site of Roker Park so you should be able to find it on Google earth.
"Westcott Terrace was on the east side of Brandling Street, between
Roker Baths Road and Cardwell Street. It will not be marked on a map as
it was part of Brandling Street. It was common in Sunderland for a row
of houses on a main road to be called a terrace and given a separate
name, probably after the builder of the houses."
On the subject of Hodgsons Buildings I'm still not sure how many houses there were now. If as you say they strecthed down towards Edmondsons Street I wasn't aware of that, I've never seen houses numbers in any census over 16 or 18 which were all still there when my wife lived there.
Anyway i've just come in from the pub so I'll have another look at all this later
regards
Brian