Number 59... but where?

I used an unusual route to find out where this house was located. Obviously it was number 59 and was on the flat, but where exactly?

The postcard was postmarked Feb 14th 1911, and was addressed to "Master Trevor Haynes, Westcote, Agnes Road, Blundellsands, Liverpool."

The message said:
"My Dear Trevor, This is where Auntie Lillie, the dog 'Togo' and Uncle Willie live in Newport Mon.
Give my love to all at your house. Auntie Lillie has been ill for 3 weeks with sciatica but is better now.
Heaps of love to you Trevor.
Willie."

First I searched for Trevor in the 1911 census. I found Alfred Trevor Haynes, age 3, living at the address on the postcard. His parents were Alfred Allen Haynes and Harriet Ann Haynes.

I then found that Trevor's mother's maiden name was Hughes. I traced her in the 1871 census, she had 3 brothers and a sister. I checked where the brothers were in 1911 and that didn't pull up anything. Then I checked the sister, Elizabeth, age just 4 months in 1871. Bingo! In 1911 she was living at 59 Corporation Road, Newport - with her husband William Edward Langshaw.

The 1911 Census added that William was "Assistant Superintendent of Railway Co."

And, if you look closely at the postcard you will see Willie standing by the side gate and Lillie holding Togo in front of the bay window... of 59 Corporation Road.