James Dickey (the author of "Deliverance") was himself an accomplished guitarist, and had quite an extensive collection of Martin guitars.

Jack Williams wrote and recorded beautiful song to commemorate Dickey's passing, called "The Old Buckdancer's Gone"

It has always annoyed me that in the book, the guitar played by the Ronnie Cox character was a Martin D-28, yet in the movie Ronnie Cox is playing an Epiphone.

Howe difficult would it have been for the producers to get that small detail correct ?