When was Mary's last appearance?

[loveinbloom]

According to IMDb, Mary's last appearance on "The Jack Benny Program" was on October 16, 1960, "Nightbeat Takeoff." She appeared in voice only in the 1963 episode "Jack Alone on New Year's Eve." But IMDb is not always complete. Are these the correct dates of Mary's final appearances?

Also, it appears that Mary's final dramatic performance was a voiceover in the November 23, 1970 "Here's Lucy" episode "Lucy and Jack Benny's Biography." She made a talk show appearance on "The Tonight Show Starring Johnny Carson" on February 16, 1978, to promote her book.