If that is his wife as you say that is buried there AND the obit you have says he is buried there, then he must be there. As I said before, his gravesite could have been overlooked at time of survey OR maybe his name & dates were never engraved on the tombstone (if it was a double headstone) thus leaving him out of survey. Or he may never have had a stone. However it bothers me knowing her's was there in older survey and now it is not. Makes me think her / his marker was overlooked because if her death date was 1965 her marker should not have deteriorated at this point ... unless it was vandelized. Any number of possibilites as to why their names are not found. Your best bet is to go and look at cemetery for yourself to see if you can find them.