there is a possible John Clews in UK National archives - see http://www.nationalarchives.gov.uk/catalogue/displaycataloguedetails.asp?CATLN=7&CATID=-3995064
Born ALDGATE, London and Middlesex
Served in 14th Foot Regiment; 80th Foot Regiment
Discharged aged 51 in 1844 - the castletown John Clews was bur 5 Jun 1856 age 64
(Eleanor bur 28 Dec 1865 age 50)