Was this JRR Tolkien's holiday home in Newcastle upon Tyne?

9 St George's Terrace, Jesmond, Newcastle upon Tyne - photographed in 2024; 

this is where JRR Tolkien's Aunt Grace and Uncle William lived.  

John Benjamin and Mary Jane Tolkien had eight children. The oldest was Arthur Reuel, who was JRR Tolkien's father. The third born was a daughter Grace Bindley Tolkien (1861–1947). 

Grace married William Charles Mountain, and they lived in the Newcastle upon Tyne area at 9 St George’s Terrace, Jesmond; South Street, Hexham; Sheriff Hill, Gateshead; and in Sydenham Terrace, Newcastle.

According to Alan Myers; Tolkien visited Newcastle upon Tyne in each of the years from 1910–1912. 

If so, then he would have stayed either at the above house in St George's terrace, or else in Sydenham Terrace, a parade of spacious properties, now demolished, which stood south of Exhibition Park. 

Part of Sydenham Terrace, Newcastle upon Tyne photographed in 1909.

These houses were evidently considerably larger (and more expensive) than that which the Mountain family had earlier inhabited in St George's Terrace - as would be expected from the increasing status and prosperity of Uncle William Mountain. 

Which of these places is most likely for the young Tolkien to have visited? It seems that the relevant part of St George's Terrace was previously called Moor View and had been built 1882-5; and Syndenham Terrace(above) was photographed in 1909 - so both houses had been built before the time of Tolkien's presumed visits in 1910-12. 

Aunt Grace apparently died in 1947 while living in Sydenham Terrace. So the question is whether she had been living there for some forty years or if in 1910 she was resident in St George's Terrace. 

Perhaps she was in Jesmond in 1910. There was still still plenty of time to move to living the other two listed houses - in Hexham and Gateshead - before finally returning to Sydenham Terrace in Newcastle.