Sharron, maybe worthwhile seeking a monumental inscription lookup for the Douglas BC cemetery for at least Mr EB Jarvis in 1973 which surely has been transcribed (not sure about as late as 1987 for Mary) as you just may strike it lucky with the daughter Vera's married name included in the inscription..if these are the right couple/family of course..... or alternatively, check the newspapers for the relevant dates for the obituary notices. Probably held in the Manx Museum