Carmela:
I am not sure if it is possible that William would have ended up in Kent in 1891 but I did find a William Arthur Stanley on the 1891 England Census who is of the right age , he is listed as a boarder and one of the other two young boarders can also be found as a British Home Child of Dr. Barnardos. The birth place of all three young boarders is recorded at N.K., which I assume means not known.
I was at the very end of a three day trial on Ancestry.com when I found this and before I was finished my time was up so I am going to have to type this from my notes which might be difficult

1891 Census:
#34 Chapel Cottages, Sandhurst, Kent
Saxby James married age 57 General Carpenter
Saxby Ann married age 55
Saxby Sydney C. single grandson 11
Stanley, William Arthur single boarder 5
Blackett, John single boarder 5
Austen, Edward single boarder 5
Could this possibly be the right young man? John Blackett (above) ended up in Oxford North, Ontario in the James Heeny household.
Hope it has some relevance...doesn't really tell you anything even if it is the right boy.
dollylee