From my perspective, assuming the gist of the story is correct ie that a group of RN sailors were sent in civilian clothes to escort a group of people out of Vladivostok, is who these people were and what was the British interest in them? The Royal Navy did embark surviving members of the Royal Family from the Crimea in 1919 on HMS Marlborough, but the British were generally very loath to take other Russian refugees - which is why most ended up in Paris, Berlin or stuck in Turkey in refugee camps until resettled in Eastern Europe in the 1920's. If a group were taken out clandestinely then who were they and to what purpose?
The British had many irons in the Russian fire at this time, including a well financed plan to purchase Russian Banks and industry in anticipation of a White victory. If the Whites had won then Britain would have had a huge financial empire in Siberia and the Don Valley that would have equalled or exceeded India - and all legal and obtained at little cost in (British) lives. Perhaps these people were the children of the Russian financiers and industrialists who sold their shares and capital interests to the British - we'll probably never know, unfortunately.
And I don't, unfortunately, have time to go looking.
Phil Tomaselli