Memphis on my mind

These photos were taken in Memphis, Tennessee aboard the Mississippi Queen Riverboat. Musician Sam Shoup is also in one of the photos.   The Mississippi Queen Riverboat is quick to advertise that Ringo was a guest on their boat, but no one says when this happened.   I would guess that these were from 1987 when Ringo was in Memphis recording the album that will never be released.  However, a performance of any type in Memphis in 1987 is not mentioned in Badman or 8 Arms to Hold you.   If they were indeed taken around the times Ringo was in Memphis in 1987, then they were either taken in February or April of that year.  

Anyone have any ideas?