Lasseter's body was found in March 1931 (Or was it? Buck would not swear to it!) and Jack published the first five editions of Lasseter's Last Ride between September 1931 and February 1932. So his work was more-or-less contemporary with the search and the later controversy surrounding Lasseter.
It has been suggested that each of the first five editions of Lasseter's Last Ride differed as new information emerged and Jack updated his first book.
I have not had time to carefully examine each edition but a cursory examination shows that different photographs were used. So there just might be truth in the suggestion that the books are different.
More to come. What do you think?