I did a search in the 1901 census for anyone by the name of Robert Williams living in Greenfield, who might have had a John Jones also living at their address, but nothing. Also looked for a John Jones who was in hospital at the time of the 1901 census. There were about 15 with that name at the Royal Naval Hospital, Haslar, and there was a John Cadwallader Jones, born Liverpool in 1870, but it wasn't the right John Jones because that one died in 1944.