It is a good idea to get certs to confirm your information, and a marriage cert will also show Eliza's father and his occupation. They are cheaper if you supply the index ref.

This index is at: www.iomfhs.im/lawsons/LawsonBMD/marriages/r_mar.html [also see Brian Lawson's other indexes on that same website]:
Marriage:
Name Date District Vol Page Spouse:
RADCLIFFE, William Alfred, 4 Mar 1897, D, bra, 682b, KEWLEY, Eliza Eleanor

BL's births have:
Name Date Parish Page Father Mother
RADCLIFFE, William Lee 17 May 1899 Douglas 1434 RADCLIFFE, William Alfred, KEWLEY, Eliza
RADCLIFFE, Winifred Fl[abbrev] 19 Apr 1898 Douglas 1358 RADCLIFFE, William Alfred, KEWLEY, Eliza Eleanor

Unfortunately most index entries are only up to 1900.

If you ask the Registry for Sidney's birth cert (giving them the date and parents - probably Eliza like the other entries) they will charge a search fee but their prices are low compared to other countries/places.

See "Contacts" at the top of their website: www.gov.im/registries/general/civilregistry/

Note Eliza's second name. I think she was ELIZA ELEANOR KEWLEY, Christening: 23 DEC 1866 Lonan, Isle Of Man, Father:LEE KEWLEY, Mother: JANE KERMEEN (IGI extracted entry from parish reg.). She gave Lonan as her place of birth on the census and probably reduced her age to that of her husband's.

Sue