I told the story of Leo the Spy three years ago. Leo Pickholz died in Lugano Switzerland in January 1972. His grave is unmarked.
Earlier today, I saw a post by Randy Seaver which introduced me to the Ancestry database "Reports of Deaths of American Citizens Abroad, 1835-1974."
I looked up Pickholz and there was one result - Leo the spy.
The database is 1835-1974 and the death is from 1972 but recorded in 1975. So the limit of the database appears based on the date of death, not the date of reporting.