Hi
I would suggest that you ask a good samaritan (Ancestry.co.za) to get you a copy of his death certificate from the Pretoria archives.
DEPOT TAB
SOURCE MHG
TYPE LEER
VOLUME_NO 0
SYSTEM 01
REFERENCE 6700/60
PART 1
DESCRIPTION WATSON, LEO RAYN.
STARTING 19600000
ENDING 19600000
REMARKS SURVIVING SPOUSE ALICE ELIZABETH WATSON.
http://www.national.archsrch.gov.za/sm300cv/smws/sm30ddf0?201206171225033B487D85&DN=00000003
DEPOT TAB
SOURCE WLD
TYPE LEER
VOLUME_NO 0
SYSTEM 01
REFERENCE 311/1934
PART 1
DESCRIPTION OPPOSED APPLICATION. ALICE ELIZABETH WATSON VERSUS LEO RYAN WATSON.
STARTING 19340000
ENDING 19340000
http://www.national.archsrch.gov.za/sm300cv/smws/sm30ddf0?201206171213243B487D85&DN=00000001
Brother could be Henry Rory Ashley Peacock Watson who died 1947 in Natal?
www.london-gazette.co.uk/issues/31616/pages/13028/page.pdf
2nd .Lt. Henry Rory A. P. Watson.