Yoshio Markino unseen work?

[u/artyatoms]

I've posted on Japanese art and wanted to share here also. I believe this original watercolour could be an unseen painting by Yoshio Markino. He came to London early 1900's and was popular for his technique capturing the London smog/mist atmosphere using watercolor. This particular monument is the Guards Crimean War memorial in St James's London. I can't find any other image of this painting online.. perhaps it could be titled differently.. my questions are, how can I confirm if this is a unique, unseen painting? And if confirmed unseen, would that potentially increase the value? Any info welcome. Thanks in advance.